Year Total
1800 6.5
1801 6.5
1802 6.49
1803 6.49
1804 6.49
1805 6.48
1806 6.48
1807 6.47
1808 6.47
1809 6.47
1810 6.46
1811 6.46
1812 6.46
1813 6.45
1814 6.45
1815 6.44
1816 6.44
1817 6.44
1818 6.43
1819 6.43
1820 6.43
1821 6.42
1822 6.42
1823 6.41
1824 6.41
1825 6.41
1826 6.4
1827 6.4
1828 6.4
1829 6.39
1830 6.39
1831 6.38
1832 6.38
1833 6.38
1834 6.37
1835 6.37
1836 6.37
1837 6.36
1838 6.36
1839 6.35
1840 6.35
1841 6.35
1842 6.34
1843 6.34
1844 6.34
1845 6.33
1846 6.33
1847 6.32
1848 6.32
1849 6.32
1850 6.31
1851 6.31
1852 6.31
1853 6.3
1854 6.3
1855 6.29
1856 6.29
1857 6.29
1858 6.28
1859 6.28
1860 6.28
1861 6.27
1862 6.27
1863 6.26
1864 6.26
1865 6.26
1866 6.25
1867 6.25
1868 6.25
1869 6.24
1870 6.24
1871 6.23
1872 6.23
1873 6.23
1874 6.22
1875 6.22
1876 6.22
1877 6.21
1878 6.21
1879 6.2
1880 6.2
1881 6.19
1882 6.18
1883 6.17
1884 6.16
1885 6.14
1886 6.13
1887 6.12
1888 6.11
1889 6.1
1890 6.09
1891 6.08
1892 6.07
1893 6.06
1894 6.04
1895 6.03
1896 6.02
1897 6.01
1898 6
1899 5.99
1900 5.98
1901 5.97
1902 5.96
1903 5.94
1904 5.93
1905 5.92
1906 5.91
1907 5.9
1908 5.89
1909 5.88
1910 5.87
1911 5.86
1912 5.84
1913 5.83
1914 5.82
1915 5.81
1916 5.8
1917 5.79
1918 5.78
1919 5.77
1920 5.76
1921 5.74
1922 5.73
1923 5.72
1924 5.71
1925 5.7
1926 5.7
1927 5.7
1928 5.7
1929 5.7
1930 5.7
1931 5.69
1932 5.67
1933 5.66
1934 5.64
1935 5.62
1936 5.6
1937 5.58
1938 5.56
1939 5.53
1940 5.51
1941 5.48
1942 5.45
1943 5.42
1944 5.38
1945 5.35
1946 5.31
1947 5.28
1948 5.24
1949 5.2
1950 5.15
1951 5.11
1952 5.07
1953 5.04
1954 5
1955 4.97
1956 4.95
1957 4.93
1958 4.92
1959 4.91
1960 4.91
1961 4.94
1962 4.97
1963 5.01
1964 5.04
1965 5.08
1966 5.11
1967 5.14
1968 5.18
1969 5.21
1970 5.25
1971 5.28
1972 5.33
1973 5.37
1974 5.42
1975 5.47
1976 5.52
1977 5.57
1978 5.62
1979 5.66
1980 5.69
1981 5.71
1982 5.72
1983 5.72
1984 5.71
1985 5.69
1986 5.65
1987 5.61
1988 5.55
1989 5.49
1990 5.42
1991 5.35
1992 5.26
1993 5.18
1994 5.09
1995 5
1996 4.9
1997 4.81
1998 4.72
1999 4.63
2000 4.54
2001 4.46
2002 4.39
2003 4.33
2004 4.27
2005 4.23
2006 4.19
2007 4.16
2008 4.14
2009 4.11
2010 4.08
2011 4.05
2012 4.01
2013 3.96
2014 3.91
2015 3.85
2016 3.79
2017 3.72
2018 3.66