Year Total
1800 4.93
1801 4.92
1802 4.91
1803 4.9
1804 4.89
1805 4.88
1806 4.87
1807 4.86
1808 4.85
1809 4.84
1810 4.82
1811 4.81
1812 4.8
1813 4.79
1814 4.78
1815 4.77
1816 4.76
1817 4.75
1818 4.74
1819 4.73
1820 4.72
1821 4.71
1822 4.7
1823 4.69
1824 4.68
1825 4.67
1826 4.66
1827 4.65
1828 4.63
1829 4.62
1830 4.61
1831 4.6
1832 4.59
1833 4.58
1834 4.57
1835 4.56
1836 4.55
1837 4.54
1838 4.53
1839 4.52
1840 4.51
1841 4.5
1842 4.49
1843 4.48
1844 4.47
1845 4.46
1846 4.44
1847 4.43
1848 4.42
1849 4.41
1850 4.4
1851 4.39
1852 4.38
1853 4.37
1854 4.36
1855 4.35
1856 4.34
1857 4.33
1858 4.21
1859 4.45
1860 3.93
1861 4.25
1862 4.12
1863 4.32
1864 4.25
1865 4.23
1866 4.32
1867 4.2
1868 4.47
1869 4.55
1870 4.59
1871 4.43
1872 4.32
1873 4.55
1874 4.42
1875 4.51
1876 4.64
1877 4.38
1878 4.3
1879 4.41
1880 4.55
1881 4.45
1882 4.51
1883 4.54
1884 4.64
1885 4.59
1886 4.68
1887 4.64
1888 4.59
1889 4.63
1890 4.26
1891 4.59
1892 4.45
1893 4.49
1894 4.49
1895 4.63
1896 4.56
1897 4.6
1898 4.45
1899 4.49
1900 4.49
1901 4.5
1902 4.58
1903 4.41
1904 4.46
1905 4.36
1906 4.39
1907 4.26
1908 4.32
1909 4.43
1910 4.36
1911 4.12
1912 4
1913 4.06
1914 3.9
1915 3.12
1916 2.34
1917 2.34
1918 2.34
1919 2.95
1920 3.54
1921 3.95
1922 3.9
1923 4.02
1924 3.94
1925 3.84
1926 3.69
1927 3.63
1928 3.56
1929 3.34
1930 3.61
1931 3.45
1932 3.43
1933 3.2
1934 3.06
1935 2.95
1936 2.96
1937 2.85
1938 2.82
1939 2.82
1940 2.84
1941 2.92
1942 2.78
1943 2.86
1944 2.51
1945 1.88
1946 2.66
1947 2.89
1948 2.89
1949 3.03
1950 2.8
1951 2.75
1952 2.67
1953 2.59
1954 2.53
1955 2.47
1956 2.43
1957 2.39
1958 2.37
1959 2.35
1960 2.34
1961 2.33
1962 2.33
1963 2.32
1964 2.31
1965 2.3
1966 2.29
1967 2.27
1968 2.26
1969 2.24
1970 2.23
1971 2.22
1972 2.21
1973 2.21
1974 2.2
1975 2.2
1976 2.18
1977 2.17
1978 2.14
1979 2.11
1980 2.06
1981 2.02
1982 1.96
1983 1.91
1984 1.85
1985 1.8
1986 1.74
1987 1.67
1988 1.61
1989 1.54
1990 1.48
1991 1.42
1992 1.37
1993 1.33
1994 1.29
1995 1.27
1996 1.25
1997 1.24
1998 1.22
1999 1.21
2000 1.21
2001 1.21
2002 1.22
2003 1.24
2004 1.27
2005 1.31
2006 1.36
2007 1.4
2008 1.44
2009 1.48
2010 1.52
2011 1.54
2012 1.57
2013 1.58
2014 1.6
2015 1.61
2016 1.63
2017 1.64
2018 1.65