Year Total
1800 5.63
1801 5.63
1802 5.64
1803 5.64
1804 5.64
1805 5.65
1806 5.65
1807 5.65
1808 5.66
1809 5.66
1810 5.66
1811 5.67
1812 5.67
1813 5.68
1814 5.68
1815 5.68
1816 5.69
1817 5.69
1818 5.69
1819 5.7
1820 5.7
1821 5.71
1822 5.71
1823 5.71
1824 5.72
1825 5.72
1826 5.72
1827 5.73
1828 5.73
1829 5.74
1830 5.74
1831 5.74
1832 5.75
1833 5.75
1834 5.75
1835 5.76
1836 5.76
1837 5.76
1838 5.77
1839 5.77
1840 5.78
1841 5.78
1842 5.78
1843 5.79
1844 5.79
1845 5.79
1846 5.8
1847 5.8
1848 5.81
1849 5.81
1850 5.81
1851 5.82
1852 5.82
1853 5.82
1854 5.83
1855 5.83
1856 5.84
1857 5.84
1858 5.84
1859 5.85
1860 5.85
1861 5.85
1862 5.86
1863 5.86
1864 5.86
1865 5.87
1866 5.87
1867 5.88
1868 5.88
1869 5.88
1870 5.89
1871 5.89
1872 5.89
1873 5.9
1874 5.9
1875 5.91
1876 5.91
1877 5.91
1878 5.92
1879 5.92
1880 5.92
1881 5.93
1882 5.93
1883 5.93
1884 5.94
1885 5.94
1886 5.95
1887 5.95
1888 5.98
1889 6.01
1890 6.04
1891 6.07
1892 6.1
1893 6.03
1894 5.97
1895 5.9
1896 5.84
1897 5.78
1898 5.74
1899 5.71
1900 5.67
1901 5.64
1902 5.6
1903 5.65
1904 5.7
1905 5.75
1906 5.79
1907 5.84
1908 5.87
1909 5.89
1910 5.91
1911 5.94
1912 5.96
1913 5.88
1914 5.8
1915 5.71
1916 5.63
1917 5.55
1918 5.54
1919 5.54
1920 5.53
1921 5.53
1922 5.52
1923 5.57
1924 5.62
1925 5.67
1926 5.72
1927 5.78
1928 5.69
1929 5.6
1930 5.52
1931 5.43
1932 5.35
1933 5.35
1934 5.36
1935 5.37
1936 5.38
1937 5.39
1938 5.42
1939 5.46
1940 5.49
1941 5.53
1942 5.56
1943 5.62
1944 5.67
1945 5.73
1946 5.79
1947 5.84
1948 6.08
1949 6.31
1950 6.54
1951 6.51
1952 6.46
1953 6.43
1954 6.41
1955 6.42
1956 6.44
1957 6.48
1958 6.53
1959 6.58
1960 6.62
1961 6.64
1962 6.63
1963 6.58
1964 6.5
1965 6.37
1966 6.2
1967 6.01
1968 5.81
1969 5.61
1970 5.4
1971 5.22
1972 5.05
1973 4.91
1974 4.78
1975 4.67
1976 4.57
1977 4.48
1978 4.39
1979 4.3
1980 4.2
1981 4.1
1982 4.01
1983 3.93
1984 3.86
1985 3.79
1986 3.73
1987 3.67
1988 3.6
1989 3.52
1990 3.45
1991 3.37
1992 3.29
1993 3.22
1994 3.15
1995 3.08
1996 3.02
1997 2.97
1998 2.92
1999 2.87
2000 2.82
2001 2.78
2002 2.74
2003 2.7
2004 2.66
2005 2.63
2006 2.6
2007 2.56
2008 2.53
2009 2.5
2010 2.47
2011 2.44
2012 2.42
2013 2.39
2014 2.37
2015 2.34
2016 2.32
2017 2.29
2018 2.27