Year Total
1800 4.7
1801 4.7
1802 4.7
1803 4.7
1804 4.7
1805 4.7
1806 4.7
1807 4.7
1808 4.7
1809 4.7
1810 4.7
1811 4.7
1812 4.7
1813 4.7
1814 4.7
1815 4.7
1816 4.7
1817 4.7
1818 4.7
1819 4.7
1820 4.7
1821 4.7
1822 4.7
1823 4.7
1824 4.7
1825 4.7
1826 4.7
1827 4.7
1828 4.7
1829 4.7
1830 4.7
1831 4.7
1832 4.7
1833 4.7
1834 4.7
1835 4.7
1836 4.7
1837 4.7
1838 4.7
1839 4.7
1840 4.7
1841 4.7
1842 4.7
1843 4.7
1844 4.7
1845 4.7
1846 4.7
1847 4.7
1848 4.7
1849 4.7
1850 4.7
1851 4.7
1852 4.7
1853 4.7
1854 4.7
1855 4.7
1856 4.7
1857 4.7
1858 4.7
1859 4.7
1860 4.7
1861 4.7
1862 4.7
1863 4.7
1864 4.7
1865 4.7
1866 4.7
1867 4.7
1868 4.7
1869 4.7
1870 4.7
1871 4.7
1872 4.7
1873 4.7
1874 4.7
1875 4.7
1876 4.7
1877 4.7
1878 4.7
1879 4.7
1880 4.7
1881 4.7
1882 4.7
1883 4.7
1884 4.7
1885 4.7
1886 4.7
1887 4.7
1888 4.7
1889 4.7
1890 4.7
1891 4.7
1892 4.7
1893 4.7
1894 4.7
1895 4.7
1896 4.7
1897 4.7
1898 4.7
1899 4.7
1900 4.7
1901 4.66
1902 4.62
1903 4.57
1904 4.53
1905 4.49
1906 4.45
1907 4.41
1908 4.36
1909 4.32
1910 4.28
1911 4.24
1912 4.2
1913 4.15
1914 4.15
1915 4.42
1916 4.42
1917 4.69
1918 4.69
1919 4.29
1920 4.15
1921 4.29
1922 4.69
1923 4.49
1924 4.76
1925 4.73
1926 4.7
1927 4.7
1928 4.66
1929 4.78
1930 5.03
1931 4.69
1932 4.69
1933 4.73
1934 5.19
1935 4.92
1936 4.97
1937 5.04
1938 5.03
1939 5.03
1940 5.02
1941 5.02
1942 5.01
1943 5
1944 5
1945 4.99
1946 4.99
1947 4.98
1948 4.97
1949 4.97
1950 4.96
1951 5.08
1952 5.31
1953 5.52
1954 5.7
1955 5.86
1956 6
1957 6.12
1958 6.21
1959 6.29
1960 6.35
1961 6.39
1962 6.43
1963 6.45
1964 6.46
1965 6.48
1966 6.49
1967 6.49
1968 6.49
1969 6.49
1970 6.47
1971 6.42
1972 6.35
1973 6.25
1974 6.13
1975 5.97
1976 5.8
1977 5.61
1978 5.42
1979 5.23
1980 5.05
1981 4.87
1982 4.69
1983 4.52
1984 4.36
1985 4.21
1986 4.06
1987 3.93
1988 3.8
1989 3.68
1990 3.55
1991 3.42
1992 3.26
1993 3.09
1994 2.9
1995 2.71
1996 2.53
1997 2.36
1998 2.21
1999 2.1
2000 2.01
2001 1.95
2002 1.92
2003 1.9
2004 1.89
2005 1.89
2006 1.9
2007 1.91
2008 1.92
2009 1.94
2010 1.95
2011 1.95
2012 1.96
2013 1.96
2014 1.96
2015 1.96
2016 1.95
2017 1.95
2018 1.95