emissions of air pollutants, annual growth rate in Mauritania
Mauritania: emissions of air pollutants, annual growth rate was 1.57 % change on previous year in 2022. ◆ Volatile
emissions of air pollutants, annual growth rate in Mauritania, 1751–2022
Source: Statizoid (derived). Measured in % change on previous year.
Analysis
In 2022, emissions of air pollutants, annual growth rate in Mauritania stood at 1.57 % change on previous year.
Compared with earlier readings it is up 100.7% on the previous year and down 68.2% over ten years.
Over the whole period, emissions of air pollutants, annual growth rate in Mauritania peaked at 198.08 % change on previous year in 1871 and was at its lowest, -6.74 % change on previous year, in 2000.
Mauritania ranks 62nd of 219 countries on this measure, 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 Mauritania, year by year
| Year | % change on previous year | Change |
|---|---|---|
| 1751 | 0.0298 % change on previous year | — |
| 1752 | 0.0298 % change on previous year | -0.0% |
| 1753 | 0.0297 % change on previous year | -0.4% |
| 1754 | 0.0298 % change on previous year | +0.3% |
| 1755 | 0.0298 % change on previous year | -0.0% |
| 1756 | 0.0298 % change on previous year | -0.0% |
| 1757 | 0.0298 % change on previous year | -0.0% |
| 1758 | 0.0297 % change on previous year | -0.4% |
| 1759 | 0.0298 % change on previous year | +0.3% |
| 1760 | 0.0298 % change on previous year | -0.0% |
| 1761 | 0.0294 % change on previous year | -1.1% |
| 1762 | 0.0294 % change on previous year | -0.0% |
| 1763 | 0.0295 % change on previous year | +0.3% |
| 1764 | 0.0294 % change on previous year | -0.4% |
| 1765 | 0.0294 % change on previous year | -0.0% |
| 1766 | 0.0295 % change on previous year | +0.3% |
| 1767 | 0.0294 % change on previous year | -0.4% |
| 1768 | 0.0294 % change on previous year | -0.0% |
| 1769 | 0.0294 % change on previous year | -0.0% |
| 1770 | 0.0295 % change on previous year | +0.3% |
| 1771 | 0.029 % change on previous year | -1.4% |
| 1772 | 0.0291 % change on previous year | +0.3% |
| 1773 | 0.029 % change on previous year | -0.4% |
| 1774 | 0.0291 % change on previous year | +0.3% |
| 1775 | 0.029 % change on previous year | -0.4% |
| 1776 | 0.0291 % change on previous year | +0.3% |
| 1777 | 0.029 % change on previous year | -0.4% |
| 1778 | 0.029 % change on previous year | -0.0% |
| 1779 | 0.0291 % change on previous year | +0.3% |
| 1780 | 0.029 % change on previous year | -0.4% |
| 1781 | 0.0287 % change on previous year | -1.1% |
| 1782 | 0.0286 % change on previous year | -0.0% |
| 1783 | 0.0287 % change on previous year | +0.3% |
| 1784 | 0.0286 % change on previous year | -0.4% |
| 1785 | 0.0286 % change on previous year | -0.0% |
| 1786 | 0.0286 % change on previous year | -0.0% |
| 1787 | 0.0286 % change on previous year | -0.0% |
| 1788 | 0.0286 % change on previous year | -0.0% |
| 1789 | 0.0286 % change on previous year | -0.0% |
| 1790 | 0.0286 % change on previous year | -0.0% |
| 1791 | 0.0283 % change on previous year | -1.1% |
| 1792 | 0.0283 % change on previous year | -0.0% |
| 1793 | 0.0281 % change on previous year | -0.4% |
| 1794 | 0.0282 % change on previous year | +0.3% |
| 1795 | 0.0281 % change on previous year | -0.4% |
| 1796 | 0.0282 % change on previous year | +0.3% |
| 1797 | 0.0281 % change on previous year | -0.4% |
| 1798 | 0.0282 % change on previous year | +0.3% |
| 1799 | 0.0281 % change on previous year | -0.4% |
| 1800 | 0.0281 % change on previous year | -0.0% |
| 1801 | 0.0278 % change on previous year | -1.1% |
| 1802 | 0.0277 % change on previous year | -0.4% |
| 1803 | 0.0278 % change on previous year | +0.3% |
| 1804 | 0.0277 % change on previous year | -0.4% |
| 1805 | 0.0276 % change on previous year | -0.0% |
| 1806 | 0.0277 % change on previous year | +0.3% |
| 1807 | 0.0276 % change on previous year | -0.4% |
| 1808 | 0.0276 % change on previous year | -0.0% |
| 1809 | 0.0277 % change on previous year | +0.3% |
| 1810 | 0.0276 % change on previous year | -0.4% |
| 1811 | 0.0777 % change on previous year | +181.5% |
| 1812 | 0.0777 % change on previous year | -0.1% |
| 1813 | 0.0777 % change on previous year | +0.1% |
| 1814 | 0.0775 % change on previous year | -0.2% |
| 1815 | 0.0775 % change on previous year | -0.1% |
| 1816 | 0.0774 % change on previous year | -0.1% |
| 1817 | 0.0773 % change on previous year | -0.2% |
| 1818 | 0.0773 % change on previous year | +0.1% |
| 1819 | 0.0772 % change on previous year | -0.1% |
| 1820 | 0.0771 % change on previous year | -0.2% |
| 1821 | 0.0771 % change on previous year | +0.1% |
| 1822 | 0.0772 % change on previous year | +0.1% |
| 1823 | 0.077 % change on previous year | -0.2% |
| 1824 | 0.0769 % change on previous year | -0.1% |
| 1825 | 0.0769 % change on previous year | -0.1% |
| 1826 | 0.0768 % change on previous year | -0.1% |
| 1827 | 0.0767 % change on previous year | -0.2% |
| 1828 | 0.0767 % change on previous year | +0.1% |
| 1829 | 0.077 % change on previous year | +0.3% |
| 1830 | 0.076 % change on previous year | -1.2% |
| 1831 | 0.0769 % change on previous year | +1.2% |
| 1832 | 0.0759 % change on previous year | -1.4% |
| 1833 | 0.0768 % change on previous year | +1.2% |
| 1834 | 0.0758 % change on previous year | -1.4% |
| 1835 | 0.0767 % change on previous year | +1.2% |
| 1836 | 0.0756 % change on previous year | -1.4% |
| 1837 | 0.0766 % change on previous year | +1.2% |
| 1838 | 0.0755 % change on previous year | -1.4% |
| 1839 | 0.0765 % change on previous year | +1.2% |
| 1840 | 0.0754 % change on previous year | -1.4% |
| 1841 | 0.0764 % change on previous year | +1.2% |
| 1842 | 0.0753 % change on previous year | -1.4% |
| 1843 | 0.0762 % change on previous year | +1.2% |
| 1844 | 0.0752 % change on previous year | -1.4% |
| 1845 | 0.0751 % change on previous year | -0.1% |
| 1846 | 0.0761 % change on previous year | +1.2% |
| 1847 | 0.075 % change on previous year | -1.4% |
| 1848 | 0.075 % change on previous year | -0.1% |
| 1849 | 0.0759 % change on previous year | +1.2% |
| 1850 | 0.0748 % change on previous year | -1.4% |
| 1851 | 0.0748 % change on previous year | -0.1% |
| 1852 | 0.0747 % change on previous year | -0.1% |
| 1853 | 0.0757 % change on previous year | +1.2% |
| 1854 | 0.0746 % change on previous year | -1.4% |
| 1855 | 0.0746 % change on previous year | -0.1% |
| 1856 | 0.0745 % change on previous year | -0.1% |
| 1857 | 0.0745 % change on previous year | -0.1% |
| 1858 | 0.0754 % change on previous year | +1.2% |
| 1859 | 0.0743 % change on previous year | -1.4% |
| 1860 | 0.0743 % change on previous year | -0.1% |
| 1861 | 0.1944 % change on previous year | +161.6% |
| 1862 | 0.194 % change on previous year | -0.2% |
| 1863 | 0.1936 % change on previous year | -0.2% |
| 1864 | 0.1923 % change on previous year | -0.7% |
| 1865 | 0.1929 % change on previous year | +0.3% |
| 1866 | 0.1925 % change on previous year | -0.2% |
| 1867 | 0.1921 % change on previous year | -0.2% |
| 1868 | 0.1908 % change on previous year | -0.7% |
| 1869 | 0.1914 % change on previous year | +0.3% |
| 1870 | 0.191 % change on previous year | -0.2% |
| 1871 | 198.08 % change on previous year | +103583.0% |
| 1872 | 0.1929 % change on previous year | -99.9% |
| 1873 | 0.1925 % change on previous year | -0.2% |
| 1874 | 0.1921 % change on previous year | -0.2% |
| 1875 | 0.1914 % change on previous year | -0.4% |
| 1876 | 0.1914 % change on previous year | -0.0% |
| 1877 | 0.1907 % change on previous year | -0.4% |
| 1878 | 0.1907 % change on previous year | -0.0% |
| 1879 | 0.19 % change on previous year | -0.4% |
| 1880 | 0.1896 % change on previous year | -0.2% |
| 1881 | 0.1924 % change on previous year | +1.5% |
| 1882 | 0.1921 % change on previous year | -0.2% |
| 1883 | 0.1914 % change on previous year | -0.4% |
| 1884 | 0.1913 % change on previous year | -0.0% |
| 1885 | 0.1906 % change on previous year | -0.4% |
| 1886 | 0.1903 % change on previous year | -0.2% |
| 1887 | 0.1902 % change on previous year | -0.0% |
| 1888 | 0.1896 % change on previous year | -0.4% |
| 1889 | 0.1892 % change on previous year | -0.2% |
| 1890 | 0.1888 % change on previous year | -0.2% |
| 1891 | 0.1916 % change on previous year | +1.5% |
| 1892 | 0.1909 % change on previous year | -0.4% |
| 1893 | 0.1909 % change on previous year | -0.0% |
| 1894 | 0.1902 % change on previous year | -0.4% |
| 1895 | 0.1901 % change on previous year | -0.0% |
| 1896 | 0.1895 % change on previous year | -0.4% |
| 1897 | 0.1894 % change on previous year | -0.0% |
| 1898 | 0.1887 % change on previous year | -0.4% |
| 1899 | 0.1887 % change on previous year | -0.0% |
| 1900 | 0.1883 % change on previous year | -0.2% |
| 1901 | -1.24 % change on previous year | -760.4% |
| 1902 | -1.25 % change on previous year | +0.7% |
| 1903 | -1.26 % change on previous year | +0.6% |
| 1904 | -1.27 % change on previous year | +0.7% |
| 1905 | -1.28 % change on previous year | +0.7% |
| 1906 | -1.29 % change on previous year | +0.7% |
| 1907 | -1.3 % change on previous year | +0.7% |
| 1908 | -1.31 % change on previous year | +0.7% |
| 1909 | -1.32 % change on previous year | +0.7% |
| 1910 | -1.32 % change on previous year | +0.7% |
| 1911 | -0.4382 % change on previous year | -66.9% |
| 1912 | 1.6 % change on previous year | -464.5% |
| 1913 | 0.6663 % change on previous year | -58.3% |
| 1914 | 0.667 % change on previous year | +0.1% |
| 1915 | 0.6683 % change on previous year | +0.2% |
| 1916 | 0.6695 % change on previous year | +0.2% |
| 1917 | 0.6714 % change on previous year | +0.3% |
| 1918 | 0.6726 % change on previous year | +0.2% |
| 1919 | 0.675 % change on previous year | +0.4% |
| 1920 | 0.6767 % change on previous year | +0.2% |
| 1921 | 1.41 % change on previous year | +109.0% |
| 1922 | 1.66 % change on previous year | +17.2% |
| 1923 | 1.65 % change on previous year | -0.3% |
| 1924 | 1.65 % change on previous year | -0.3% |
| 1925 | 1.64 % change on previous year | -0.3% |
| 1926 | 1.64 % change on previous year | -0.3% |
| 1927 | 1.59 % change on previous year | -3.2% |
| 1928 | 1.58 % change on previous year | -0.2% |
| 1929 | 1.58 % change on previous year | -0.2% |
| 1930 | 1.58 % change on previous year | -0.2% |
| 1931 | 1.65 % change on previous year | +5.0% |
| 1932 | 3.28 % change on previous year | +98.3% |
| 1933 | 1.43 % change on previous year | -56.3% |
| 1934 | 1.43 % change on previous year | -0.3% |
| 1935 | 1.82 % change on previous year | +27.7% |
| 1936 | 2.79 % change on previous year | +52.8% |
| 1937 | -0.8122 % change on previous year | -129.1% |
| 1938 | 0.3654 % change on previous year | -145.0% |
| 1939 | 0.3928 % change on previous year | +7.5% |
| 1940 | 0.4197 % change on previous year | +6.8% |
| 1941 | 2.74 % change on previous year | +551.8% |
| 1942 | 1.51 % change on previous year | -44.9% |
| 1943 | 1.5 % change on previous year | -0.4% |
| 1944 | 5.32 % change on previous year | +253.9% |
| 1945 | 5.64 % change on previous year | +6.0% |
| 1946 | 4.18 % change on previous year | -25.9% |
| 1947 | 4.3 % change on previous year | +2.9% |
| 1948 | 4.42 % change on previous year | +2.9% |
| 1949 | 4.55 % change on previous year | +2.9% |
| 1950 | 5.75 % change on previous year | +26.2% |
| 1951 | -2.74 % change on previous year | -147.6% |
| 1952 | -1.43 % change on previous year | -47.7% |
| 1953 | -2.25 % change on previous year | +57.2% |
| 1954 | -2.26 % change on previous year | +0.6% |
| 1955 | -2.56 % change on previous year | +13.1% |
| 1956 | -2.66 % change on previous year | +4.1% |
| 1957 | -2.98 % change on previous year | +11.8% |
| 1958 | -4.83 % change on previous year | +62.3% |
| 1959 | -2.89 % change on previous year | -40.2% |
| 1960 | -4.16 % change on previous year | +43.8% |
| 1961 | -4.83 % change on previous year | +16.3% |
| 1962 | -5.28 % change on previous year | +9.2% |
| 1963 | -5.69 % change on previous year | +7.7% |
| 1964 | -6.41 % change on previous year | +12.7% |
| 1965 | -6.51 % change on previous year | +1.6% |
| 1966 | 3.08 % change on previous year | -147.3% |
| 1967 | 2.95 % change on previous year | -4.2% |
| 1968 | 2.87 % change on previous year | -2.9% |
| 1969 | 3.27 % change on previous year | +14.3% |
| 1970 | 5.48 % change on previous year | +67.2% |
| 1971 | 1.22 % change on previous year | -77.7% |
| 1972 | 4.88 % change on previous year | +300.3% |
| 1973 | 3.73 % change on previous year | -23.6% |
| 1974 | 1.54 % change on previous year | -58.8% |
| 1975 | 6.17 % change on previous year | +301.6% |
| 1976 | 5.78 % change on previous year | -6.4% |
| 1977 | 4.94 % change on previous year | -14.4% |
| 1978 | 3.51 % change on previous year | -29.0% |
| 1979 | 2.24 % change on previous year | -36.0% |
| 1980 | 3.34 % change on previous year | +48.8% |
| 1981 | 3.59 % change on previous year | +7.5% |
| 1982 | 8.61 % change on previous year | +139.8% |
| 1983 | 2.57 % change on previous year | -70.1% |
| 1984 | 2.22 % change on previous year | -13.6% |
| 1985 | -2.03 % change on previous year | -191.2% |
| 1986 | -1.72 % change on previous year | -14.9% |
| 1987 | 45.28 % change on previous year | -2725.9% |
| 1988 | 13.17 % change on previous year | -70.9% |
| 1989 | -3.98 % change on previous year | -130.2% |
| 1990 | 12.3 % change on previous year | -408.8% |
| 1991 | 0.9541 % change on previous year | -92.2% |
| 1992 | 0.4491 % change on previous year | -52.9% |
| 1993 | -3.7 % change on previous year | -923.5% |
| 1994 | 7.72 % change on previous year | -308.7% |
| 1995 | 3.73 % change on previous year | -51.7% |
| 1996 | 1.01 % change on previous year | -72.9% |
| 1997 | -0.1658 % change on previous year | -116.4% |
| 1998 | 1.98 % change on previous year | -1291.6% |
| 1999 | 4.28 % change on previous year | +116.6% |
| 2000 | -6.74 % change on previous year | -257.4% |
| 2001 | 2.89 % change on previous year | -142.9% |
| 2002 | 3.33 % change on previous year | +15.0% |
| 2003 | 2.84 % change on previous year | -14.5% |
| 2004 | 3.41 % change on previous year | +20.0% |
| 2005 | 3.88 % change on previous year | +13.7% |
| 2006 | 2.92 % change on previous year | -24.7% |
| 2007 | 3.89 % change on previous year | +33.2% |
| 2008 | 5.07 % change on previous year | +30.2% |
| 2009 | 3.25 % change on previous year | -35.9% |
| 2010 | 2.16 % change on previous year | -33.5% |
| 2011 | 3.92 % change on previous year | +81.5% |
| 2012 | 4.92 % change on previous year | +25.5% |
| 2013 | -0.5715 % change on previous year | -111.6% |
| 2014 | 3.63 % change on previous year | -735.8% |
| 2015 | 0.7713 % change on previous year | -78.8% |
| 2016 | 0.7318 % change on previous year | -5.1% |
| 2017 | 2.24 % change on previous year | +205.9% |
| 2018 | -0.5081 % change on previous year | -122.7% |
| 2019 | 2.98 % change on previous year | -686.8% |
| 2020 | 0.8237 % change on previous year | -72.4% |
| 2021 | 0.7802 % change on previous year | -5.3% |
| 2022 | 1.57 % change on previous year | +100.7% |
Mauritania compared with similar countries
- Mauritania's 1.57 % change on previous year is above the median for lower middle income countries, which is 0.5856 % change on previous year, 2.7× the median. (46 countries reporting)
- Mauritania's 1.57 % change on previous year is above the median for Sub-Saharan Africa, which is 0.9871 % change on previous year, 1.6× the median. (48 countries reporting)
Biggest year-on-year movements
Years where emissions of air pollutants, annual growth rate in Mauritania 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 |
|---|---|---|---|
| 1871 | +103583.0% | 0.191 % change on previous year | 198.08 % change on previous year |
| 1987 | +2725.9% | -1.72 % change on previous year | 45.28 % change on previous year |
| 1998 | +1291.6% | -0.1658 % change on previous year | 1.98 % change on previous year |
| 1993 | -923.5% | 0.4491 % change on previous year | -3.7 % change on previous year |
| 1901 | -760.4% | 0.1883 % change on previous year | -1.24 % change on previous year |
| 2014 | +735.8% | -0.5715 % change on previous year | 3.63 % change on previous year |
Averages by decade
| Decade | Average | Lowest | Highest | Years |
|---|---|---|---|---|
| 1750s | 0.0298 % change on previous year | 0.0297 % change on previous year | 0.0298 % change on previous year | 9 |
| 1760s | 0.0295 % change on previous year | 0.0294 % change on previous year | 0.0298 % change on previous year | 10 |
| 1770s | 0.0291 % change on previous year | 0.029 % change on previous year | 0.0295 % change on previous year | 10 |
| 1780s | 0.0287 % change on previous year | 0.0286 % change on previous year | 0.029 % change on previous year | 10 |
| 1790s | 0.0282 % change on previous year | 0.0281 % change on previous year | 0.0286 % change on previous year | 10 |
| 1800s | 0.0277 % change on previous year | 0.0276 % change on previous year | 0.0281 % change on previous year | 10 |
| 1810s | 0.0725 % change on previous year | 0.0276 % change on previous year | 0.0777 % change on previous year | 10 |
| 1820s | 0.0769 % change on previous year | 0.0767 % change on previous year | 0.0772 % change on previous year | 10 |
| 1830s | 0.0762 % change on previous year | 0.0755 % change on previous year | 0.0769 % change on previous year | 10 |
| 1840s | 0.0756 % change on previous year | 0.075 % change on previous year | 0.0764 % change on previous year | 10 |
| 1850s | 0.0748 % change on previous year | 0.0743 % change on previous year | 0.0757 % change on previous year | 10 |
| 1860s | 0.1808 % change on previous year | 0.0743 % change on previous year | 0.1944 % change on previous year | 10 |
| 1870s | 19.98 % change on previous year | 0.19 % change on previous year | 198.08 % change on previous year | 10 |
| 1880s | 0.1907 % change on previous year | 0.1892 % change on previous year | 0.1924 % change on previous year | 10 |
| 1890s | 0.1899 % change on previous year | 0.1887 % change on previous year | 0.1916 % change on previous year | 10 |
| 1900s | -1.13 % change on previous year | -1.32 % change on previous year | 0.1883 % change on previous year | 10 |
| 1910s | 0.4524 % change on previous year | -1.32 % change on previous year | 1.6 % change on previous year | 10 |
| 1920s | 1.51 % change on previous year | 0.6767 % change on previous year | 1.66 % change on previous year | 10 |
| 1930s | 1.39 % change on previous year | -0.8122 % change on previous year | 3.28 % change on previous year | 10 |
| 1940s | 3.46 % change on previous year | 0.4197 % change on previous year | 5.64 % change on previous year | 10 |
| 1950s | -1.89 % change on previous year | -4.83 % change on previous year | 5.75 % change on previous year | 10 |
| 1960s | -2.07 % change on previous year | -6.51 % change on previous year | 3.27 % change on previous year | 10 |
| 1970s | 3.95 % change on previous year | 1.22 % change on previous year | 6.17 % change on previous year | 10 |
| 1980s | 7.1 % change on previous year | -3.98 % change on previous year | 45.28 % change on previous year | 10 |
| 1990s | 2.85 % change on previous year | -3.7 % change on previous year | 12.3 % change on previous year | 10 |
| 2000s | 2.47 % change on previous year | -6.74 % change on previous year | 5.07 % change on previous year | 10 |
| 2010s | 2.03 % change on previous year | -0.5715 % change on previous year | 4.92 % change on previous year | 10 |
| 2020s | 1.06 % change on previous year | 0.7802 % change on previous year | 1.57 % change on previous year | 3 |
Countries ranked near Mauritania
More climate change data for Mauritania
- Nutrient nitrogen N (total) — Synthetic fertilizers (Agricultural) 5.05 million kg (2050)
- Emissions from livestock — Emissions (CO2eq) 13,025 kt (2050)
- Emissions from livestock — Emissions (CO2eq) from N2O 3,939 kt (2050)
- Emissions from livestock — Emissions (CO2eq) from CH4 9,086 kt (2050)
- Emissions from livestock — Emissions 14.87 kt (2050)
- Emissions from livestock — Emissions 324.5 kt (2050)
- Emissions from crops — Emissions (CO2eq) 339.5 kt (2050)
- Emissions from crops — Emissions (CO2eq) from N2O 60.39 kt (2050)
- Emissions from crops — Emissions (CO2eq) from CH4 279.11 kt (2050)
- Emissions from crops — Emissions 0.2279 kt (2050)
Frequently asked questions
- What is emissions of air pollutants, annual growth rate in Mauritania?
- Emissions of air pollutants, annual growth rate in Mauritania was 1.57 % change on previous year in 2022, according to Statizoid (derived).
- What is the highest emissions of air pollutants, annual growth rate recorded in Mauritania?
- The highest recorded value was 198.08 % change on previous year in 1871.
- What is the lowest emissions of air pollutants, annual growth rate recorded in Mauritania?
- The lowest recorded value was -6.74 % change on previous year in 2000.
- How does Mauritania rank for emissions of air pollutants, annual growth rate?
- Mauritania ranks 62nd out of 219 countries with data for 2022.
- Is emissions of air pollutants, annual growth rate rising or falling in Mauritania?
- Over the last ten years it is down 68.2%. The long-run trend across the full record is volatile.
- Where does this Mauritania 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.