Year Total
1800 6.52
1801 6.52
1802 6.52
1803 6.52
1804 6.52
1805 6.52
1806 6.52
1807 6.52
1808 6.52
1809 6.52
1810 6.52
1811 6.52
1812 6.52
1813 6.52
1814 6.52
1815 6.52
1816 6.52
1817 6.52
1818 6.52
1819 6.52
1820 6.52
1821 6.52
1822 6.52
1823 6.52
1824 6.52
1825 6.52
1826 6.52
1827 6.52
1828 6.52
1829 6.52
1830 6.52
1831 6.52
1832 6.52
1833 6.52
1834 6.52
1835 6.52
1836 6.52
1837 6.52
1838 6.52
1839 6.52
1840 6.52
1841 6.52
1842 6.52
1843 6.52
1844 6.52
1845 6.52
1846 6.52
1847 6.52
1848 6.52
1849 6.52
1850 6.52
1851 6.52
1852 6.52
1853 6.52
1854 6.52
1855 6.52
1856 6.52
1857 6.52
1858 6.52
1859 6.52
1860 6.52
1861 6.52
1862 6.52
1863 6.52
1864 6.52
1865 6.52
1866 6.52
1867 6.52
1868 6.52
1869 6.52
1870 6.52
1871 6.52
1872 6.52
1873 6.52
1874 6.52
1875 6.52
1876 6.52
1877 6.52
1878 6.52
1879 6.52
1880 6.52
1881 6.52
1882 6.52
1883 6.52
1884 6.52
1885 6.52
1886 6.52
1887 6.52
1888 6.52
1889 6.52
1890 6.52
1891 6.52
1892 6.52
1893 6.52
1894 6.52
1895 6.52
1896 6.52
1897 6.52
1898 6.52
1899 6.52
1900 6.52
1901 6.52
1902 6.52
1903 6.52
1904 6.52
1905 6.52
1906 6.52
1907 6.52
1908 6.52
1909 6.52
1910 6.52
1911 6.52
1912 6.52
1913 6.52
1914 6.52
1915 6.52
1916 6.52
1917 6.52
1918 6.52
1919 6.52
1920 6.52
1921 6.52
1922 6.52
1923 6.52
1924 6.52
1925 6.52
1926 6.52
1927 6.52
1928 6.52
1929 6.52
1930 6.52
1931 6.52
1932 6.52
1933 6.52
1934 6.52
1935 6.52
1936 6.52
1937 6.51
1938 6.51
1939 6.51
1940 6.51
1941 6.51
1942 6.51
1943 6.51
1944 6.51
1945 6.51
1946 6.51
1947 6.51
1948 6.51
1949 6.51
1950 6.51
1951 6.49
1952 6.45
1953 6.42
1954 6.4
1955 6.38
1956 6.37
1957 6.36
1958 6.37
1959 6.37
1960 6.37
1961 6.38
1962 6.38
1963 6.37
1964 6.35
1965 6.31
1966 6.27
1967 6.21
1968 6.13
1969 6.04
1970 5.92
1971 5.75
1972 5.54
1973 5.3
1974 5.04
1975 4.79
1976 4.61
1977 4.51
1978 4.51
1979 4.61
1980 4.77
1981 4.96
1982 5.13
1983 5.26
1984 5.32
1985 5.34
1986 5.31
1987 5.27
1988 5.26
1989 5.27
1990 5.34
1991 5.47
1992 5.65
1993 5.87
1994 6.13
1995 6.38
1996 6.63
1997 6.83
1998 6.99
1999 7.08
2000 7.11
2001 7.09
2002 7.04
2003 6.97
2004 6.88
2005 6.79
2006 6.69
2007 6.59
2008 6.48
2009 6.36
2010 6.23
2011 6.11
2012 5.98
2013 5.86
2014 5.74
2015 5.62
2016 5.5
2017 5.39
2018 5.28