emissions of air pollutants, annual growth rate in Gambia
Gambia: emissions of air pollutants, annual growth rate was 1.4 % change on previous year in 2022. ◆ Volatile
emissions of air pollutants, annual growth rate in Gambia, 1751–2022
Source: Statizoid (derived). Measured in % change on previous year.
Analysis
Gambia recorded 1.4 % change on previous year for emissions of air pollutants, annual growth rate in 2022.
Compared with earlier readings it is down 3.2% on the previous year and down 49.1% over ten years.
Over the whole period, emissions of air pollutants, annual growth rate in Gambia peaked at 48.92 % change on previous year in 1892 and was at its lowest, -28.7 % change on previous year, in 1891.
That places Gambia 68th out of 219 countries with data for 2022, putting it in the middle of the range.
The series is highly variable year to year, so single readings are best treated with caution.
emissions of air pollutants, annual growth rate in Gambia, year by year
| Year | % change on previous year | Change |
|---|---|---|
| 1751 | -0.9873 % change on previous year | — |
| 1752 | -0.9969 % change on previous year | +1.0% |
| 1753 | -1.01 % change on previous year | +1.0% |
| 1754 | -1.02 % change on previous year | +1.0% |
| 1755 | -1.03 % change on previous year | +1.0% |
| 1756 | -1.04 % change on previous year | +1.0% |
| 1757 | -1.05 % change on previous year | +1.0% |
| 1758 | -1.06 % change on previous year | +1.0% |
| 1759 | -1.07 % change on previous year | +1.1% |
| 1760 | -1.08 % change on previous year | +1.0% |
| 1761 | -0.9889 % change on previous year | -8.5% |
| 1762 | -0.9983 % change on previous year | +0.9% |
| 1763 | -1.01 % change on previous year | +1.0% |
| 1764 | -1.02 % change on previous year | +1.0% |
| 1765 | -1.03 % change on previous year | +1.0% |
| 1766 | -1.04 % change on previous year | +1.0% |
| 1767 | -1.05 % change on previous year | +1.0% |
| 1768 | -1.06 % change on previous year | +1.0% |
| 1769 | -1.07 % change on previous year | +1.0% |
| 1770 | -1.08 % change on previous year | +1.1% |
| 1771 | -0.9907 % change on previous year | -8.4% |
| 1772 | -1 % change on previous year | +0.9% |
| 1773 | -1.01 % change on previous year | +1.0% |
| 1774 | -1.02 % change on previous year | +1.0% |
| 1775 | -1.03 % change on previous year | +1.0% |
| 1776 | -1.04 % change on previous year | +1.0% |
| 1777 | -1.05 % change on previous year | +1.0% |
| 1778 | -1.06 % change on previous year | +1.0% |
| 1779 | -1.07 % change on previous year | +1.0% |
| 1780 | -1.08 % change on previous year | +1.0% |
| 1781 | -0.9928 % change on previous year | -8.4% |
| 1782 | -1 % change on previous year | +0.9% |
| 1783 | -1.01 % change on previous year | +1.0% |
| 1784 | -1.02 % change on previous year | +1.0% |
| 1785 | -1.03 % change on previous year | +1.0% |
| 1786 | -1.04 % change on previous year | +1.0% |
| 1787 | -1.05 % change on previous year | +1.0% |
| 1788 | -1.06 % change on previous year | +1.0% |
| 1789 | -1.07 % change on previous year | +1.0% |
| 1790 | -1.09 % change on previous year | +1.0% |
| 1791 | -0.9947 % change on previous year | -8.4% |
| 1792 | -1 % change on previous year | +1.0% |
| 1793 | -1.01 % change on previous year | +0.9% |
| 1794 | -1.02 % change on previous year | +1.0% |
| 1795 | -1.03 % change on previous year | +1.0% |
| 1796 | -1.04 % change on previous year | +0.9% |
| 1797 | -1.05 % change on previous year | +1.1% |
| 1798 | -1.07 % change on previous year | +1.0% |
| 1799 | -1.08 % change on previous year | +1.0% |
| 1800 | -1.09 % change on previous year | +1.1% |
| 1801 | -0.997 % change on previous year | -8.3% |
| 1802 | -1.01 % change on previous year | +1.0% |
| 1803 | -1.02 % change on previous year | +0.9% |
| 1804 | -1.03 % change on previous year | +1.0% |
| 1805 | -1.04 % change on previous year | +1.0% |
| 1806 | -1.05 % change on previous year | +1.0% |
| 1807 | -1.06 % change on previous year | +1.0% |
| 1808 | -1.07 % change on previous year | +1.0% |
| 1809 | -1.08 % change on previous year | +1.0% |
| 1810 | -1.09 % change on previous year | +1.0% |
| 1811 | 0.0547 % change on previous year | -105.0% |
| 1812 | 0.0551 % change on previous year | +0.7% |
| 1813 | 0.0547 % change on previous year | -0.8% |
| 1814 | 0.055 % change on previous year | +0.7% |
| 1815 | 0.0546 % change on previous year | -0.8% |
| 1816 | 0.0546 % change on previous year | -0.1% |
| 1817 | 0.0545 % change on previous year | -0.1% |
| 1818 | 0.0545 % change on previous year | -0.1% |
| 1819 | 0.0541 % change on previous year | -0.8% |
| 1820 | 0.0545 % change on previous year | +0.7% |
| 1821 | 0.052 % change on previous year | -4.5% |
| 1822 | 0.052 % change on previous year | -0.1% |
| 1823 | 0.052 % change on previous year | -0.1% |
| 1824 | 0.0519 % change on previous year | -0.1% |
| 1825 | 0.0519 % change on previous year | -0.1% |
| 1826 | 0.0519 % change on previous year | -0.1% |
| 1827 | 0.0514 % change on previous year | -0.8% |
| 1828 | 0.0518 % change on previous year | +0.7% |
| 1829 | 0.0514 % change on previous year | -0.8% |
| 1830 | 0.0514 % change on previous year | -0.1% |
| 1831 | 0.0489 % change on previous year | -4.7% |
| 1832 | 0.0489 % change on previous year | -0.0% |
| 1833 | 0.0489 % change on previous year | -0.0% |
| 1834 | 0.0489 % change on previous year | -0.0% |
| 1835 | 0.0484 % change on previous year | -0.9% |
| 1836 | 0.0488 % change on previous year | +0.8% |
| 1837 | 0.0484 % change on previous year | -0.9% |
| 1838 | 0.0484 % change on previous year | -0.0% |
| 1839 | 0.0483 % change on previous year | -0.0% |
| 1840 | 0.0483 % change on previous year | -0.0% |
| 1841 | 0.0455 % change on previous year | -5.8% |
| 1842 | 0.0455 % change on previous year | -0.0% |
| 1843 | 0.0455 % change on previous year | -0.0% |
| 1844 | 0.045 % change on previous year | -0.9% |
| 1845 | 0.0454 % change on previous year | +0.8% |
| 1846 | 0.045 % change on previous year | -0.9% |
| 1847 | 0.045 % change on previous year | -0.0% |
| 1848 | 0.045 % change on previous year | -0.0% |
| 1849 | 0.0445 % change on previous year | -0.9% |
| 1850 | 0.0449 % change on previous year | +0.8% |
| 1851 | 0.0421 % change on previous year | -6.2% |
| 1852 | 0.0421 % change on previous year | -0.0% |
| 1853 | 0.0421 % change on previous year | -0.0% |
| 1854 | 0.0421 % change on previous year | -0.0% |
| 1855 | 0.0421 % change on previous year | -0.0% |
| 1856 | 0.0416 % change on previous year | -1.0% |
| 1857 | 0.042 % change on previous year | +0.9% |
| 1858 | 0.0416 % change on previous year | -1.0% |
| 1859 | 0.042 % change on previous year | +0.9% |
| 1860 | 0.0416 % change on previous year | -1.0% |
| 1861 | 0.1583 % change on previous year | +280.8% |
| 1862 | 0.1576 % change on previous year | -0.4% |
| 1863 | 0.1578 % change on previous year | +0.1% |
| 1864 | 0.1567 % change on previous year | -0.7% |
| 1865 | 0.1569 % change on previous year | +0.1% |
| 1866 | 0.1563 % change on previous year | -0.4% |
| 1867 | 0.156 % change on previous year | -0.2% |
| 1868 | 0.1558 % change on previous year | -0.2% |
| 1869 | 0.1551 % change on previous year | -0.4% |
| 1870 | 0.1549 % change on previous year | -0.2% |
| 1871 | 1.07 % change on previous year | +593.6% |
| 1872 | 0.1538 % change on previous year | -85.7% |
| 1873 | 0.1535 % change on previous year | -0.2% |
| 1874 | 0.1529 % change on previous year | -0.4% |
| 1875 | 0.1527 % change on previous year | -0.2% |
| 1876 | 0.1521 % change on previous year | -0.4% |
| 1877 | 0.1522 % change on previous year | +0.1% |
| 1878 | 0.1516 % change on previous year | -0.4% |
| 1879 | 0.1514 % change on previous year | -0.2% |
| 1880 | 0.1508 % change on previous year | -0.4% |
| 1881 | 0.1502 % change on previous year | -0.4% |
| 1882 | 0.1496 % change on previous year | -0.4% |
| 1883 | 0.149 % change on previous year | -0.4% |
| 1884 | 0.1491 % change on previous year | +0.1% |
| 1885 | 0.1485 % change on previous year | -0.4% |
| 1886 | 4.8 % change on previous year | +3132.3% |
| 1887 | 7.79 % change on previous year | +62.3% |
| 1888 | 7.79 % change on previous year | +0.0% |
| 1889 | 7.79 % change on previous year | +0.0% |
| 1890 | 7.79 % change on previous year | +0.0% |
| 1891 | -28.7 % change on previous year | -468.2% |
| 1892 | 48.92 % change on previous year | -270.5% |
| 1893 | 3.05 % change on previous year | -93.8% |
| 1894 | 3.05 % change on previous year | -0.0% |
| 1895 | 3.05 % change on previous year | +0.0% |
| 1896 | 3.05 % change on previous year | +0.0% |
| 1897 | 3.05 % change on previous year | +0.0% |
| 1898 | 3.05 % change on previous year | +0.0% |
| 1899 | 3.05 % change on previous year | +0.1% |
| 1900 | 3.05 % change on previous year | +0.1% |
| 1901 | -0.7773 % change on previous year | -125.5% |
| 1902 | 8.09 % change on previous year | -1140.6% |
| 1903 | 3.57 % change on previous year | -55.9% |
| 1904 | 3.57 % change on previous year | +0.1% |
| 1905 | 3.57 % change on previous year | +0.1% |
| 1906 | 3.58 % change on previous year | +0.1% |
| 1907 | 3.58 % change on previous year | +0.1% |
| 1908 | 3.58 % change on previous year | +0.1% |
| 1909 | 3.59 % change on previous year | +0.1% |
| 1910 | 3.6 % change on previous year | +0.1% |
| 1911 | 9.24 % change on previous year | +157.2% |
| 1912 | -2.32 % change on previous year | -125.1% |
| 1913 | 1.86 % change on previous year | -180.3% |
| 1914 | 2.34 % change on previous year | +25.9% |
| 1915 | 2.35 % change on previous year | +0.3% |
| 1916 | 2.36 % change on previous year | +0.3% |
| 1917 | 2.36 % change on previous year | +0.3% |
| 1918 | 2.37 % change on previous year | +0.3% |
| 1919 | 2.38 % change on previous year | +0.3% |
| 1920 | 2.39 % change on previous year | +0.3% |
| 1921 | 20.73 % change on previous year | +768.8% |
| 1922 | -11.49 % change on previous year | -155.5% |
| 1923 | 3.35 % change on previous year | -129.1% |
| 1924 | 3.33 % change on previous year | -0.4% |
| 1925 | 3.32 % change on previous year | -0.5% |
| 1926 | 3.3 % change on previous year | -0.5% |
| 1927 | 3.29 % change on previous year | -0.5% |
| 1928 | -0.6164 % change on previous year | -118.8% |
| 1929 | -0.5534 % change on previous year | -10.2% |
| 1930 | -0.4901 % change on previous year | -11.4% |
| 1931 | 0.3345 % change on previous year | -168.2% |
| 1932 | 2.14 % change on previous year | +540.4% |
| 1933 | 2.35 % change on previous year | +9.8% |
| 1934 | 1.92 % change on previous year | -18.5% |
| 1935 | 2.55 % change on previous year | +33.4% |
| 1936 | 2.12 % change on previous year | -17.0% |
| 1937 | 2.82 % change on previous year | +33.2% |
| 1938 | 2.79 % change on previous year | -1.2% |
| 1939 | -3.24 % change on previous year | -216.3% |
| 1940 | 8.7 % change on previous year | -368.3% |
| 1941 | 2.76 % change on previous year | -68.2% |
| 1942 | 2.73 % change on previous year | -1.0% |
| 1943 | 2.37 % change on previous year | -13.5% |
| 1944 | 2.69 % change on previous year | +13.5% |
| 1945 | -2.67 % change on previous year | -199.3% |
| 1946 | 12.36 % change on previous year | -563.4% |
| 1947 | 2.98 % change on previous year | -75.9% |
| 1948 | 2.47 % change on previous year | -17.0% |
| 1949 | 3.01 % change on previous year | +21.8% |
| 1950 | 5.13 % change on previous year | +70.1% |
| 1951 | -1.56 % change on previous year | -130.5% |
| 1952 | -1.84 % change on previous year | +17.5% |
| 1953 | -1.48 % change on previous year | -19.5% |
| 1954 | -1.16 % change on previous year | -21.6% |
| 1955 | -1.56 % change on previous year | +34.4% |
| 1956 | -1.35 % change on previous year | -13.1% |
| 1957 | -1.59 % change on previous year | +17.8% |
| 1958 | -1.94 % change on previous year | +21.6% |
| 1959 | -3.39 % change on previous year | +75.1% |
| 1960 | -3.3 % change on previous year | -2.7% |
| 1961 | -3.98 % change on previous year | +20.5% |
| 1962 | -4.48 % change on previous year | +12.5% |
| 1963 | -5.06 % change on previous year | +13.1% |
| 1964 | -6.18 % change on previous year | +22.1% |
| 1965 | -6.61 % change on previous year | +7.0% |
| 1966 | 4.45 % change on previous year | -167.4% |
| 1967 | 3.86 % change on previous year | -13.3% |
| 1968 | 4.13 % change on previous year | +7.0% |
| 1969 | 4.96 % change on previous year | +19.9% |
| 1970 | 3.71 % change on previous year | -25.2% |
| 1971 | 6.68 % change on previous year | +80.2% |
| 1972 | 5.91 % change on previous year | -11.5% |
| 1973 | 3.32 % change on previous year | -43.8% |
| 1974 | 0.9616 % change on previous year | -71.1% |
| 1975 | 8.89 % change on previous year | +824.9% |
| 1976 | 4.07 % change on previous year | -54.2% |
| 1977 | 4.2 % change on previous year | +3.0% |
| 1978 | 5.88 % change on previous year | +40.3% |
| 1979 | 2.96 % change on previous year | -49.8% |
| 1980 | 3.53 % change on previous year | +19.4% |
| 1981 | 4.67 % change on previous year | +32.2% |
| 1982 | 3.17 % change on previous year | -32.1% |
| 1983 | 2.4 % change on previous year | -24.4% |
| 1984 | 3.9 % change on previous year | +62.9% |
| 1985 | 3.33 % change on previous year | -14.6% |
| 1986 | 6.56 % change on previous year | +96.9% |
| 1987 | 5.64 % change on previous year | -14.1% |
| 1988 | 6.12 % change on previous year | +8.6% |
| 1989 | 1.96 % change on previous year | -68.0% |
| 1990 | 4.22 % change on previous year | +115.6% |
| 1991 | 3.46 % change on previous year | -17.9% |
| 1992 | -0.7389 % change on previous year | -121.3% |
| 1993 | -1.96 % change on previous year | +164.7% |
| 1994 | 7.12 % change on previous year | -464.0% |
| 1995 | 2.3 % change on previous year | -67.7% |
| 1996 | -0.2245 % change on previous year | -109.7% |
| 1997 | -0.7749 % change on previous year | +245.2% |
| 1998 | 0.6792 % change on previous year | -187.6% |
| 1999 | 2.91 % change on previous year | +327.8% |
| 2000 | 21.84 % change on previous year | +651.8% |
| 2001 | 1.91 % change on previous year | -91.3% |
| 2002 | 1.49 % change on previous year | -21.8% |
| 2003 | 1.45 % change on previous year | -3.1% |
| 2004 | 1.93 % change on previous year | +33.4% |
| 2005 | 2.56 % change on previous year | +32.3% |
| 2006 | 2.53 % change on previous year | -1.1% |
| 2007 | 2.18 % change on previous year | -13.9% |
| 2008 | 2.25 % change on previous year | +3.5% |
| 2009 | 2.96 % change on previous year | +31.6% |
| 2010 | 2.21 % change on previous year | -25.4% |
| 2011 | 2.85 % change on previous year | +29.0% |
| 2012 | 2.76 % change on previous year | -3.4% |
| 2013 | 0.6024 % change on previous year | -78.1% |
| 2014 | 1.87 % change on previous year | +210.6% |
| 2015 | 0.1237 % change on previous year | -93.4% |
| 2016 | 0.1494 % change on previous year | +20.8% |
| 2017 | 1.63 % change on previous year | +988.3% |
| 2018 | -0.6013 % change on previous year | -137.0% |
| 2019 | 2.72 % change on previous year | -553.0% |
| 2020 | 1.43 % change on previous year | -47.5% |
| 2021 | 1.45 % change on previous year | +1.4% |
| 2022 | 1.4 % change on previous year | -3.2% |
Gambia compared with similar countries
- Gambia's 1.4 % change on previous year is above the median for low income countries, which is 0.8496 % change on previous year, 1.7× the median. (25 countries reporting)
- Gambia's 1.4 % change on previous year is above the median for Sub-Saharan Africa, which is 0.9871 % change on previous year, 1.4× the median. (48 countries reporting)
Biggest year-on-year movements
Years where emissions of air pollutants, annual growth rate in Gambia changed far more than this series normally does. A large move can be a real event or a change in how the figure was measured — the source note below says who published it.
| Year | Change | From | To |
|---|---|---|---|
| 1886 | +3132.3% | 0.1485 % change on previous year | 4.8 % change on previous year |
| 1902 | +1140.6% | -0.7773 % change on previous year | 8.09 % change on previous year |
| 2017 | +988.3% | 0.1494 % change on previous year | 1.63 % change on previous year |
| 1975 | +824.9% | 0.9616 % change on previous year | 8.89 % change on previous year |
| 1921 | +768.8% | 2.39 % change on previous year | 20.73 % change on previous year |
| 2000 | +651.8% | 2.91 % change on previous year | 21.84 % change on previous year |
Averages by decade
| Decade | Average | Lowest | Highest | Years |
|---|---|---|---|---|
| 1750s | -1.03 % change on previous year | -1.07 % change on previous year | -0.9873 % change on previous year | 9 |
| 1760s | -1.03 % change on previous year | -1.08 % change on previous year | -0.9889 % change on previous year | 10 |
| 1770s | -1.04 % change on previous year | -1.08 % change on previous year | -0.9907 % change on previous year | 10 |
| 1780s | -1.04 % change on previous year | -1.08 % change on previous year | -0.9928 % change on previous year | 10 |
| 1790s | -1.04 % change on previous year | -1.09 % change on previous year | -0.9947 % change on previous year | 10 |
| 1800s | -1.04 % change on previous year | -1.09 % change on previous year | -0.997 % change on previous year | 10 |
| 1810s | -0.0598 % change on previous year | -1.09 % change on previous year | 0.0551 % change on previous year | 10 |
| 1820s | 0.0521 % change on previous year | 0.0514 % change on previous year | 0.0545 % change on previous year | 10 |
| 1830s | 0.0489 % change on previous year | 0.0483 % change on previous year | 0.0514 % change on previous year | 10 |
| 1840s | 0.0455 % change on previous year | 0.0445 % change on previous year | 0.0483 % change on previous year | 10 |
| 1850s | 0.0423 % change on previous year | 0.0416 % change on previous year | 0.0449 % change on previous year | 10 |
| 1860s | 0.1452 % change on previous year | 0.0416 % change on previous year | 0.1583 % change on previous year | 10 |
| 1870s | 0.245 % change on previous year | 0.1514 % change on previous year | 1.07 % change on previous year | 10 |
| 1880s | 2.91 % change on previous year | 0.1485 % change on previous year | 7.79 % change on previous year | 10 |
| 1890s | 4.93 % change on previous year | -28.7 % change on previous year | 48.92 % change on previous year | 10 |
| 1900s | 3.54 % change on previous year | -0.7773 % change on previous year | 8.09 % change on previous year | 10 |
| 1910s | 2.65 % change on previous year | -2.32 % change on previous year | 9.24 % change on previous year | 10 |
| 1920s | 2.7 % change on previous year | -11.49 % change on previous year | 20.73 % change on previous year | 10 |
| 1930s | 1.33 % change on previous year | -3.24 % change on previous year | 2.82 % change on previous year | 10 |
| 1940s | 3.74 % change on previous year | -2.67 % change on previous year | 12.36 % change on previous year | 10 |
| 1950s | -1.07 % change on previous year | -3.39 % change on previous year | 5.13 % change on previous year | 10 |
| 1960s | -1.22 % change on previous year | -6.61 % change on previous year | 4.96 % change on previous year | 10 |
| 1970s | 4.66 % change on previous year | 0.9616 % change on previous year | 8.89 % change on previous year | 10 |
| 1980s | 4.13 % change on previous year | 1.96 % change on previous year | 6.56 % change on previous year | 10 |
| 1990s | 1.7 % change on previous year | -1.96 % change on previous year | 7.12 % change on previous year | 10 |
| 2000s | 4.11 % change on previous year | 1.45 % change on previous year | 21.84 % change on previous year | 10 |
| 2010s | 1.43 % change on previous year | -0.6013 % change on previous year | 2.85 % change on previous year | 10 |
| 2020s | 1.43 % change on previous year | 1.4 % change on previous year | 1.45 % change on previous year | 3 |
Countries ranked near Gambia
- 65 Guyana 1.51 % change on previous year compare
- 66 Djibouti 1.48 % change on previous year compare
- 67 Sao Tome and Principe 1.43 % change on previous year compare
- 69 Zambia 1.4 % change on previous year compare
- 70 Singapore 1.39 % change on previous year compare
- 71 Namibia 1.38 % change on previous year compare
More climate change data for Gambia
- Nutrient nitrogen N (total) — Synthetic fertilizers (Agricultural) 7.29 million kg (2050)
- Emissions from livestock — Emissions (CO2eq) 1,177 kt (2050)
- Emissions from livestock — Emissions (CO2eq) from N2O 380.7 kt (2050)
- Emissions from livestock — Emissions (CO2eq) from CH4 795.99 kt (2050)
- Emissions from livestock — Emissions 1.44 kt (2050)
- Emissions from livestock — Emissions 28.43 kt (2050)
- Emissions from crops — Emissions (CO2eq) 275.94 kt (2050)
- Emissions from crops — Emissions (CO2eq) from N2O 74.92 kt (2050)
- Emissions from crops — Emissions (CO2eq) from CH4 201.03 kt (2050)
- Emissions from crops — Emissions 0.2827 kt (2050)
Frequently asked questions
- What is emissions of air pollutants, annual growth rate in Gambia?
- Emissions of air pollutants, annual growth rate in Gambia was 1.4 % change on previous year in 2022, according to Statizoid (derived).
- What is the highest emissions of air pollutants, annual growth rate recorded in Gambia?
- The highest recorded value was 48.92 % change on previous year in 1892.
- What is the lowest emissions of air pollutants, annual growth rate recorded in Gambia?
- The lowest recorded value was -28.7 % change on previous year in 1891.
- How does Gambia rank for emissions of air pollutants, annual growth rate?
- Gambia ranks 68th out of 219 countries with data for 2022.
- Is emissions of air pollutants, annual growth rate rising or falling in Gambia?
- Over the last ten years it is down 49.1%. The long-run trend across the full record is volatile.
- Where does this Gambia data come from?
- The figures come from Statizoid (derived), published as part of emissions of air pollutants, annual growth rate. Statizoid updates them automatically from the source API.
Download this data
CSV · JSON — 272 observations, free to reuse under Derived by Statizoid from the sources named on the page.
How this figure is calculated
The year-on-year percentage change in emissions of air pollutants. Computed from consecutive annual observations; years either side of a gap are skipped rather than bridged.
Computed from
- emissions of air pollutants Hoesly et al. (2024) – Community Emissions Data System (CEDS) – with major processing by Our World in Data
Statizoid computes this series; the underlying measurements belong to the publishers named above. The arithmetic is applied to every country and year where both inputs report, and nothing is estimated unless the page says so.
About this data
The year-on-year percentage change in emissions of air pollutants. Computed from consecutive annual observations; years either side of a gap are skipped rather than bridged.