Year Total
1800 6.7
1801 6.7
1802 6.7
1803 6.7
1804 6.7
1805 6.7
1806 6.7
1807 6.7
1808 6.7
1809 6.7
1810 6.7
1811 6.7
1812 6.7
1813 6.7
1814 6.7
1815 6.7
1816 6.7
1817 6.7
1818 6.7
1819 6.7
1820 6.7
1821 6.7
1822 6.7
1823 6.7
1824 6.7
1825 6.7
1826 6.7
1827 6.7
1828 6.7
1829 6.7
1830 6.7
1831 6.7
1832 6.7
1833 6.7
1834 6.7
1835 6.7
1836 6.7
1837 6.7
1838 6.7
1839 6.7
1840 6.7
1841 6.7
1842 6.7
1843 6.7
1844 6.7
1845 6.7
1846 6.7
1847 6.7
1848 6.7
1849 6.7
1850 6.7
1851 6.7
1852 6.7
1853 6.7
1854 6.7
1855 6.7
1856 6.7
1857 6.7
1858 6.7
1859 6.7
1860 6.7
1861 6.7
1862 6.7
1863 6.7
1864 6.7
1865 6.7
1866 6.7
1867 6.7
1868 6.7
1869 6.7
1870 6.7
1871 6.7
1872 6.7
1873 6.7
1874 6.7
1875 6.7
1876 6.7
1877 6.7
1878 6.7
1879 6.7
1880 6.7
1881 6.7
1882 6.7
1883 6.7
1884 6.7
1885 6.7
1886 6.7
1887 6.7
1888 6.7
1889 6.7
1890 6.7
1891 6.7
1892 6.7
1893 6.7
1894 6.7
1895 6.7
1896 6.7
1897 6.7
1898 6.7
1899 6.7
1900 6.7
1901 6.7
1902 6.7
1903 6.7
1904 6.7
1905 6.7
1906 6.7
1907 6.7
1908 6.7
1909 6.7
1910 6.7
1911 6.7
1912 6.7
1913 6.7
1914 6.7
1915 6.7
1916 6.7
1917 6.7
1918 6.7
1919 6.7
1920 6.7
1921 6.7
1922 6.7
1923 6.7
1924 6.7
1925 6.7
1926 6.68
1927 6.66
1928 6.64
1929 6.63
1930 6.61
1931 6.59
1932 6.57
1933 6.55
1934 6.53
1935 6.51
1936 6.49
1937 6.48
1938 6.46
1939 6.44
1940 6.42
1941 6.4
1942 6.38
1943 6.36
1944 6.35
1945 6.33
1946 6.31
1947 6.29
1948 6.27
1949 6.25
1950 6.23
1951 6.27
1952 6.33
1953 6.39
1954 6.45
1955 6.5
1956 6.56
1957 6.6
1958 6.65
1959 6.69
1960 6.73
1961 6.76
1962 6.79
1963 6.83
1964 6.85
1965 6.88
1966 6.9
1967 6.92
1968 6.94
1969 6.95
1970 6.95
1971 6.94
1972 6.93
1973 6.9
1974 6.87
1975 6.82
1976 6.76
1977 6.68
1978 6.59
1979 6.48
1980 6.36
1981 6.22
1982 6.06
1983 5.89
1984 5.71
1985 5.52
1986 5.33
1987 5.13
1988 4.93
1989 4.74
1990 4.55
1991 4.37
1992 4.2
1993 4.03
1994 3.88
1995 3.73
1996 3.6
1997 3.47
1998 3.35
1999 3.23
2000 3.12
2001 3.01
2002 2.91
2003 2.8
2004 2.7
2005 2.61
2006 2.52
2007 2.44
2008 2.38
2009 2.32
2010 2.28
2011 2.24
2012 2.21
2013 2.18
2014 2.16
2015 2.13
2016 2.1
2017 2.08
2018 2.05