Year Total
1800 6.47
1801 6.47
1802 6.47
1803 6.47
1804 6.47
1805 6.47
1806 6.47
1807 6.47
1808 6.47
1809 6.47
1810 6.47
1811 6.47
1812 6.47
1813 6.47
1814 6.47
1815 6.47
1816 6.47
1817 6.47
1818 6.47
1819 6.47
1820 6.47
1821 6.47
1822 6.48
1823 6.48
1824 6.48
1825 6.48
1826 6.48
1827 6.48
1828 6.48
1829 6.48
1830 6.48
1831 6.48
1832 6.48
1833 6.48
1834 6.48
1835 6.48
1836 6.48
1837 6.48
1838 6.48
1839 6.48
1840 6.48
1841 6.48
1842 6.48
1843 6.48
1844 6.48
1845 6.48
1846 6.48
1847 6.48
1848 6.48
1849 6.48
1850 6.48
1851 6.48
1852 6.48
1853 6.48
1854 6.48
1855 6.48
1856 6.48
1857 6.48
1858 6.49
1859 6.49
1860 6.49
1861 6.49
1862 6.49
1863 6.49
1864 6.49
1865 6.49
1866 6.49
1867 6.49
1868 6.49
1869 6.49
1870 6.49
1871 6.49
1872 6.49
1873 6.49
1874 6.49
1875 6.49
1876 6.49
1877 6.49
1878 6.49
1879 6.49
1880 6.49
1881 6.49
1882 6.49
1883 6.49
1884 6.49
1885 6.49
1886 6.49
1887 6.49
1888 6.49
1889 6.49
1890 6.49
1891 6.49
1892 6.49
1893 6.5
1894 6.5
1895 6.5
1896 6.5
1897 6.5
1898 6.5
1899 6.5
1900 6.5
1901 6.5
1902 6.5
1903 6.5
1904 6.5
1905 6.5
1906 6.5
1907 6.5
1908 6.5
1909 6.5
1910 6.5
1911 6.5
1912 6.5
1913 6.5
1914 6.5
1915 6.5
1916 6.5
1917 6.5
1918 6.5
1919 6.5
1920 6.5
1921 6.5
1922 6.5
1923 6.5
1924 6.5
1925 6.5
1926 6.5
1927 6.5
1928 6.5
1929 6.5
1930 6.5
1931 6.5
1932 6.49
1933 6.49
1934 6.49
1935 6.49
1936 6.49
1937 6.49
1938 6.49
1939 6.48
1940 6.48
1941 6.48
1942 6.48
1943 6.48
1944 6.48
1945 6.48
1946 6.47
1947 6.47
1948 6.47
1949 6.47
1950 6.47
1951 6.48
1952 6.49
1953 6.51
1954 6.52
1955 6.54
1956 6.55
1957 6.57
1958 6.58
1959 6.6
1960 6.62
1961 6.63
1962 6.65
1963 6.67
1964 6.68
1965 6.69
1966 6.7
1967 6.7
1968 6.69
1969 6.67
1970 6.65
1971 6.62
1972 6.58
1973 6.55
1974 6.51
1975 6.47
1976 6.43
1977 6.39
1978 6.35
1979 6.29
1980 6.21
1981 6.11
1982 5.98
1983 5.83
1984 5.64
1985 5.45
1986 5.24
1987 5.04
1988 4.85
1989 4.69
1990 4.54
1991 4.41
1992 4.29
1993 4.18
1994 4.06
1995 3.95
1996 3.84
1997 3.72
1998 3.61
1999 3.49
2000 3.39
2001 3.29
2002 3.19
2003 3.11
2004 3.04
2005 2.99
2006 2.95
2007 2.92
2008 2.9
2009 2.89
2010 2.88
2011 2.88
2012 2.86
2013 2.84
2014 2.81
2015 2.77
2016 2.73
2017 2.68
2018 2.64