Year Total
1800 6.91
1801 6.91
1802 6.91
1803 6.91
1804 6.91
1805 6.91
1806 6.91
1807 6.91
1808 6.91
1809 6.91
1810 6.91
1811 6.91
1812 6.91
1813 6.91
1814 6.91
1815 6.91
1816 6.91
1817 6.91
1818 6.91
1819 6.91
1820 6.91
1821 6.91
1822 6.91
1823 6.91
1824 6.91
1825 6.91
1826 6.91
1827 6.91
1828 6.91
1829 6.91
1830 6.91
1831 6.91
1832 6.91
1833 6.91
1834 6.91
1835 6.91
1836 6.91
1837 6.91
1838 6.91
1839 6.91
1840 6.91
1841 6.91
1842 6.91
1843 6.91
1844 6.91
1845 6.91
1846 6.91
1847 6.91
1848 6.91
1849 6.91
1850 6.91
1851 6.91
1852 6.91
1853 6.91
1854 6.91
1855 6.91
1856 6.91
1857 6.91
1858 6.91
1859 6.91
1860 6.91
1861 6.91
1862 6.91
1863 6.91
1864 6.91
1865 6.91
1866 6.91
1867 6.91
1868 6.91
1869 6.91
1870 6.91
1871 6.91
1872 6.91
1873 6.91
1874 6.91
1875 6.91
1876 6.91
1877 6.91
1878 6.91
1879 6.91
1880 6.91
1881 6.91
1882 6.91
1883 6.91
1884 6.91
1885 6.91
1886 6.91
1887 6.91
1888 6.91
1889 6.91
1890 6.91
1891 6.91
1892 6.91
1893 6.91
1894 6.91
1895 6.91
1896 6.91
1897 6.91
1898 6.91
1899 6.91
1900 6.91
1901 6.91
1902 6.91
1903 6.91
1904 6.91
1905 6.91
1906 6.91
1907 6.91
1908 6.91
1909 6.91
1910 6.91
1911 6.91
1912 6.91
1913 6.91
1914 6.91
1915 6.91
1916 6.91
1917 6.91
1918 6.91
1919 6.91
1920 6.91
1921 6.91
1922 6.91
1923 6.91
1924 6.91
1925 6.91
1926 6.93
1927 6.94
1928 6.96
1929 6.98
1930 7
1931 7.02
1932 7.03
1933 7.05
1934 7.07
1935 7.09
1936 7.11
1937 7.12
1938 7.14
1939 7.16
1940 7.18
1941 7.2
1942 7.22
1943 7.23
1944 7.25
1945 7.27
1946 7.29
1947 7.31
1948 7.32
1949 7.34
1950 7.36
1951 7.39
1952 7.45
1953 7.51
1954 7.57
1955 7.64
1956 7.7
1957 7.76
1958 7.83
1959 7.89
1960 7.95
1961 8
1962 8.04
1963 8.08
1964 8.1
1965 8.12
1966 8.13
1967 8.13
1968 8.12
1969 8.1
1970 8.08
1971 8.05
1972 8.01
1973 7.96
1974 7.91
1975 7.84
1976 7.77
1977 7.7
1978 7.62
1979 7.54
1980 7.46
1981 7.37
1982 7.27
1983 7.16
1984 7.04
1985 6.91
1986 6.76
1987 6.6
1988 6.43
1989 6.24
1990 6.07
1991 5.9
1992 5.76
1993 5.63
1994 5.54
1995 5.46
1996 5.4
1997 5.35
1998 5.3
1999 5.24
2000 5.18
2001 5.11
2002 5.04
2003 4.98
2004 4.91
2005 4.84
2006 4.76
2007 4.68
2008 4.58
2009 4.48
2010 4.37
2011 4.27
2012 4.17
2013 4.07
2014 3.99
2015 3.92
2016 3.85
2017 3.79
2018 3.74