Year Total
1800 7.8
1801 7.8
1802 7.8
1803 7.8
1804 7.8
1805 7.8
1806 7.8
1807 7.8
1808 7.8
1809 7.8
1810 7.8
1811 7.8
1812 7.8
1813 7.8
1814 7.8
1815 7.8
1816 7.8
1817 7.8
1818 7.8
1819 7.8
1820 7.8
1821 7.8
1822 7.8
1823 7.8
1824 7.8
1825 7.8
1826 7.8
1827 7.8
1828 7.8
1829 7.8
1830 7.8
1831 7.8
1832 7.8
1833 7.8
1834 7.8
1835 7.8
1836 7.8
1837 7.8
1838 7.8
1839 7.8
1840 7.8
1841 7.8
1842 7.8
1843 7.8
1844 7.8
1845 7.8
1846 7.8
1847 7.8
1848 7.8
1849 7.8
1850 7.8
1851 7.8
1852 7.8
1853 7.8
1854 7.8
1855 7.8
1856 7.8
1857 7.8
1858 7.8
1859 7.8
1860 7.8
1861 7.8
1862 7.8
1863 7.8
1864 7.8
1865 7.8
1866 7.8
1867 7.8
1868 7.8
1869 7.8
1870 7.8
1871 7.8
1872 7.8
1873 7.8
1874 7.8
1875 7.8
1876 7.8
1877 7.8
1878 7.8
1879 7.8
1880 7.8
1881 7.8
1882 7.8
1883 7.8
1884 7.8
1885 7.8
1886 7.8
1887 7.8
1888 7.8
1889 7.8
1890 7.8
1891 7.8
1892 7.8
1893 7.8
1894 7.8
1895 7.8
1896 7.8
1897 7.8
1898 7.8
1899 7.8
1900 7.8
1901 7.72
1902 7.65
1903 7.57
1904 7.49
1905 7.42
1906 7.34
1907 7.26
1908 7.19
1909 7.11
1910 7.03
1911 6.96
1912 6.88
1913 6.8
1914 6.73
1915 6.65
1916 6.57
1917 6.5
1918 6.42
1919 6.34
1920 6.27
1921 6.19
1922 6.11
1923 6.04
1924 5.96
1925 5.88
1926 5.81
1927 5.73
1928 5.65
1929 5.58
1930 5.5
1931 5.32
1932 5.13
1933 4.95
1934 4.77
1935 4.59
1936 4.4
1937 4.22
1938 4.04
1939 3.85
1940 3.67
1941 3.61
1942 3.56
1943 3.5
1944 3.44
1945 3.39
1946 3.33
1947 3.27
1948 3.21
1949 3.16
1950 3.1
1951 3.04
1952 2.97
1953 2.92
1954 2.9
1955 2.89
1956 2.9
1957 2.91
1958 2.93
1959 2.94
1960 2.94
1961 2.94
1962 2.94
1963 2.92
1964 2.91
1965 2.88
1966 2.85
1967 2.82
1968 2.79
1969 2.75
1970 2.71
1971 2.67
1972 2.62
1973 2.58
1974 2.53
1975 2.49
1976 2.45
1977 2.41
1978 2.37
1979 2.34
1980 2.31
1981 2.3
1982 2.28
1983 2.28
1984 2.28
1985 2.27
1986 2.27
1987 2.26
1988 2.24
1989 2.22
1990 2.18
1991 2.13
1992 2.08
1993 2.01
1994 1.95
1995 1.88
1996 1.81
1997 1.75
1998 1.69
1999 1.64
2000 1.61
2001 1.59
2002 1.59
2003 1.6
2004 1.63
2005 1.66
2006 1.71
2007 1.77
2008 1.82
2009 1.87
2010 1.92
2011 1.95
2012 1.98
2013 2
2014 2
2015 2
2016 2
2017 1.99
2018 1.98