Year Total
1800 6.86
1801 6.86
1802 6.86
1803 6.86
1804 6.86
1805 6.86
1806 6.86
1807 6.86
1808 6.86
1809 6.86
1810 6.86
1811 6.86
1812 6.86
1813 6.86
1814 6.86
1815 6.86
1816 6.86
1817 6.86
1818 6.86
1819 6.86
1820 6.86
1821 6.86
1822 6.86
1823 6.86
1824 6.86
1825 6.86
1826 6.86
1827 6.86
1828 6.86
1829 6.86
1830 6.86
1831 6.86
1832 6.86
1833 6.86
1834 6.86
1835 6.86
1836 6.86
1837 6.86
1838 6.86
1839 6.86
1840 6.86
1841 6.86
1842 6.86
1843 6.86
1844 6.86
1845 6.86
1846 6.86
1847 6.86
1848 6.86
1849 6.86
1850 6.86
1851 6.86
1852 6.86
1853 6.86
1854 6.86
1855 6.86
1856 6.86
1857 6.86
1858 6.86
1859 6.86
1860 6.86
1861 6.86
1862 6.86
1863 6.86
1864 6.86
1865 6.86
1866 6.86
1867 6.86
1868 6.86
1869 6.86
1870 6.86
1871 6.86
1872 6.86
1873 6.86
1874 6.86
1875 6.86
1876 6.86
1877 6.86
1878 6.86
1879 6.86
1880 6.86
1881 6.86
1882 6.86
1883 6.86
1884 6.86
1885 6.86
1886 6.86
1887 6.86
1888 6.86
1889 6.86
1890 6.86
1891 6.86
1892 6.86
1893 6.86
1894 6.86
1895 6.86
1896 6.86
1897 6.86
1898 6.86
1899 6.86
1900 6.86
1901 6.86
1902 6.86
1903 6.86
1904 6.86
1905 6.86
1906 6.86
1907 6.86
1908 6.86
1909 6.86
1910 6.86
1911 6.86
1912 6.86
1913 6.86
1914 6.86
1915 6.86
1916 6.86
1917 6.86
1918 6.86
1919 6.86
1920 6.86
1921 6.86
1922 6.86
1923 6.86
1924 6.86
1925 6.86
1926 6.87
1927 6.89
1928 6.9
1929 6.91
1930 6.93
1931 6.94
1932 6.96
1933 6.97
1934 6.98
1935 7
1936 7.01
1937 7.02
1938 7.04
1939 7.05
1940 7.06
1941 7.08
1942 7.09
1943 7.1
1944 7.12
1945 7.13
1946 7.15
1947 7.16
1948 7.17
1949 7.19
1950 7.2
1951 7.19
1952 7.18
1953 7.17
1954 7.16
1955 7.16
1956 7.17
1957 7.17
1958 7.19
1959 7.2
1960 7.22
1961 7.23
1962 7.24
1963 7.25
1964 7.26
1965 7.26
1966 7.26
1967 7.26
1968 7.27
1969 7.27
1970 7.28
1971 7.29
1972 7.3
1973 7.31
1974 7.31
1975 7.31
1976 7.31
1977 7.3
1978 7.28
1979 7.25
1980 7.21
1981 7.14
1982 7.05
1983 6.93
1984 6.8
1985 6.65
1986 6.5
1987 6.34
1988 6.19
1989 6.05
1990 5.91
1991 5.76
1992 5.59
1993 5.41
1994 5.2
1995 4.98
1996 4.75
1997 4.53
1998 4.33
1999 4.14
2000 3.97
2001 3.83
2002 3.71
2003 3.6
2004 3.51
2005 3.42
2006 3.33
2007 3.24
2008 3.15
2009 3.06
2010 2.96
2011 2.87
2012 2.78
2013 2.7
2014 2.64
2015 2.58
2016 2.53
2017 2.49
2018 2.45