Year Total
1800 6.51
1801 6.51
1802 6.51
1803 6.51
1804 6.51
1805 6.51
1806 6.51
1807 6.51
1808 6.51
1809 6.51
1810 6.51
1811 6.51
1812 6.51
1813 6.51
1814 6.51
1815 6.51
1816 6.51
1817 6.51
1818 6.51
1819 6.51
1820 6.51
1821 6.51
1822 6.51
1823 6.51
1824 6.51
1825 6.51
1826 6.51
1827 6.51
1828 6.51
1829 6.51
1830 6.51
1831 6.51
1832 6.51
1833 6.51
1834 6.51
1835 6.51
1836 6.51
1837 6.51
1838 6.51
1839 6.51
1840 6.51
1841 6.51
1842 6.51
1843 6.51
1844 6.51
1845 6.51
1846 6.51
1847 6.51
1848 6.51
1849 6.51
1850 6.51
1851 6.51
1852 6.51
1853 6.51
1854 6.51
1855 6.51
1856 6.51
1857 6.51
1858 6.51
1859 6.51
1860 6.51
1861 6.51
1862 6.51
1863 6.51
1864 6.51
1865 6.51
1866 6.51
1867 6.51
1868 6.51
1869 6.51
1870 6.51
1871 6.51
1872 6.51
1873 6.51
1874 6.51
1875 6.51
1876 6.51
1877 6.51
1878 6.51
1879 6.51
1880 6.51
1881 6.51
1882 6.51
1883 6.51
1884 6.51
1885 6.51
1886 6.51
1887 6.51
1888 6.51
1889 6.51
1890 6.51
1891 6.51
1892 6.51
1893 6.51
1894 6.51
1895 6.51
1896 6.51
1897 6.51
1898 6.51
1899 6.51
1900 6.51
1901 6.51
1902 6.51
1903 6.51
1904 6.51
1905 6.51
1906 6.51
1907 6.51
1908 6.51
1909 6.51
1910 6.51
1911 6.51
1912 6.51
1913 6.51
1914 6.51
1915 6.51
1916 6.51
1917 6.51
1918 6.51
1919 6.51
1920 6.51
1921 6.51
1922 6.51
1923 6.51
1924 6.51
1925 6.51
1926 6.54
1927 6.57
1928 6.6
1929 6.62
1930 6.65
1931 6.68
1932 6.7
1933 6.73
1934 6.76
1935 6.78
1936 6.81
1937 6.84
1938 6.87
1939 6.89
1940 6.92
1941 6.95
1942 6.97
1943 7
1944 7.03
1945 7.05
1946 7.08
1947 7.11
1948 7.14
1949 7.16
1950 7.19
1951 7.11
1952 6.97
1953 6.85
1954 6.76
1955 6.69
1956 6.64
1957 6.62
1958 6.61
1959 6.61
1960 6.61
1961 6.6
1962 6.57
1963 6.51
1964 6.4
1965 6.25
1966 6.04
1967 5.77
1968 5.46
1969 5.12
1970 4.77
1971 4.42
1972 4.1
1973 3.81
1974 3.58
1975 3.39
1976 3.25
1977 3.13
1978 3.04
1979 2.96
1980 2.89
1981 2.84
1982 2.8
1983 2.77
1984 2.75
1985 2.74
1986 2.72
1987 2.7
1988 2.66
1989 2.61
1990 2.56
1991 2.5
1992 2.44
1993 2.4
1994 2.36
1995 2.34
1996 2.33
1997 2.33
1998 2.34
1999 2.36
2000 2.38
2001 2.4
2002 2.42
2003 2.43
2004 2.43
2005 2.43
2006 2.42
2007 2.42
2008 2.41
2009 2.41
2010 2.41
2011 2.4
2012 2.4
2013 2.38
2014 2.37
2015 2.35
2016 2.32
2017 2.29
2018 2.27