Year Total
1800 4.44
1801 4.44
1802 4.44
1803 4.44
1804 4.44
1805 4.44
1806 4.44
1807 4.44
1808 4.44
1809 4.44
1810 4.44
1811 4.44
1812 4.44
1813 4.44
1814 4.44
1815 4.45
1816 4.46
1817 4.46
1818 4.47
1819 4.48
1820 4.49
1821 4.49
1822 4.5
1823 4.51
1824 4.52
1825 4.52
1826 4.53
1827 4.54
1828 4.55
1829 4.55
1830 4.56
1831 4.57
1832 4.58
1833 4.58
1834 4.59
1835 4.6
1836 4.61
1837 4.61
1838 4.62
1839 4.63
1840 4.64
1841 4.64
1842 4.65
1843 4.66
1844 4.67
1845 4.67
1846 4.68
1847 4.69
1848 4.7
1849 4.7
1850 4.71
1851 4.72
1852 4.73
1853 4.73
1854 4.74
1855 4.75
1856 4.76
1857 4.76
1858 4.77
1859 4.78
1860 4.79
1861 4.79
1862 4.8
1863 4.81
1864 4.82
1865 4.82
1866 4.83
1867 4.84
1868 4.85
1869 4.85
1870 4.86
1871 4.87
1872 4.88
1873 4.88
1874 4.89
1875 4.9
1876 4.91
1877 4.91
1878 4.92
1879 4.93
1880 4.94
1881 4.94
1882 4.95
1883 4.96
1884 4.89
1885 4.82
1886 4.72
1887 4.61
1888 4.5
1889 4.4
1890 4.29
1891 4.36
1892 4.43
1893 4.5
1894 4.57
1895 4.64
1896 4.69
1897 4.74
1898 4.8
1899 4.85
1900 4.9
1901 4.91
1902 4.92
1903 4.92
1904 4.93
1905 4.93
1906 4.81
1907 4.69
1908 4.57
1909 4.45
1910 4.33
1911 4.33
1912 4.33
1913 4.33
1914 4.34
1915 4.34
1916 4.34
1917 4.26
1918 4.19
1919 4.11
1920 4.03
1921 4.11
1922 4.19
1923 4.27
1924 4.36
1925 4.44
1926 4.36
1927 4.28
1928 4.2
1929 4.12
1930 4.04
1931 3.96
1932 3.89
1933 4.06
1934 4.23
1935 4.41
1936 4.31
1937 4.21
1938 4.36
1939 4.5
1940 4.65
1941 4.78
1942 4.91
1943 5.04
1944 5.16
1945 5.29
1946 5.29
1947 5.29
1948 5.28
1949 5.28
1950 5.28
1951 5.28
1952 5.29
1953 5.31
1954 5.32
1955 5.33
1956 5.34
1957 5.34
1958 5.34
1959 5.32
1960 5.26
1961 5.18
1962 5.05
1963 4.87
1964 4.66
1965 4.43
1966 4.2
1967 3.99
1968 3.8
1969 3.66
1970 3.55
1971 3.48
1972 3.43
1973 3.39
1974 3.35
1975 3.31
1976 3.29
1977 3.27
1978 3.27
1979 3.28
1980 3.28
1981 3.28
1982 3.26
1983 3.22
1984 3.15
1985 3.06
1986 2.95
1987 2.83
1988 2.7
1989 2.57
1990 2.45
1991 2.34
1992 2.23
1993 2.13
1994 2.04
1995 1.96
1996 1.9
1997 1.84
1998 1.8
1999 1.77
2000 1.75
2001 1.74
2002 1.74
2003 1.75
2004 1.76
2005 1.77
2006 1.78
2007 1.79
2008 1.8
2009 1.8
2010 1.81
2011 1.8
2012 1.8
2013 1.79
2014 1.78
2015 1.77
2016 1.75
2017 1.74
2018 1.73