Year Total
1800 5.5
1801 5.5
1802 5.5
1803 5.5
1804 5.5
1805 5.5
1806 5.5
1807 5.5
1808 5.5
1809 5.5
1810 5.5
1811 5.5
1812 5.5
1813 5.5
1814 5.5
1815 5.5
1816 5.5
1817 5.5
1818 5.5
1819 5.5
1820 5.5
1821 5.5
1822 5.5
1823 5.5
1824 5.5
1825 5.5
1826 5.5
1827 5.5
1828 5.5
1829 5.5
1830 5.5
1831 5.5
1832 5.5
1833 5.5
1834 5.5
1835 5.5
1836 5.5
1837 5.5
1838 5.5
1839 5.5
1840 5.5
1841 5.5
1842 5.5
1843 5.5
1844 5.5
1845 5.5
1846 5.5
1847 5.5
1848 5.5
1849 5.5
1850 5.5
1851 5.5
1852 5.5
1853 5.5
1854 5.5
1855 5.5
1856 5.5
1857 5.5
1858 5.5
1859 5.5
1860 5.5
1861 5.5
1862 5.5
1863 5.5
1864 5.5
1865 5.5
1866 5.5
1867 5.5
1868 5.5
1869 5.5
1870 5.5
1871 5.5
1872 5.5
1873 5.5
1874 5.5
1875 5.5
1876 5.5
1877 5.5
1878 5.5
1879 5.5
1880 5.5
1881 5.5
1882 5.5
1883 5.5
1884 5.5
1885 5.5
1886 5.5
1887 5.5
1888 5.5
1889 5.5
1890 5.5
1891 5.5
1892 5.5
1893 5.5
1894 5.5
1895 5.5
1896 5.5
1897 5.5
1898 5.5
1899 5.5
1900 5.5
1901 5.5
1902 5.5
1903 5.5
1904 5.5
1905 5.5
1906 5.5
1907 5.5
1908 5.5
1909 5.5
1910 5.5
1911 5.5
1912 5.5
1913 5.5
1914 5.5
1915 5.5
1916 5.5
1917 5.5
1918 5.5
1919 5.5
1920 5.5
1921 5.5
1922 5.5
1923 5.5
1924 5.5
1925 5.5
1926 5.5
1927 5.5
1928 5.5
1929 5.5
1930 5.5
1931 5.48
1932 5.45
1933 5.43
1934 5.4
1935 5.38
1936 5.35
1937 5.33
1938 5.3
1939 5.28
1940 5.25
1941 5.15
1942 5.06
1943 4.96
1944 4.86
1945 4.77
1946 5
1947 5.2
1948 4.91
1949 5.54
1950 5.29
1951 5.26
1952 5.97
1953 5.67
1954 5.96
1955 5.98
1956 5.61
1957 6.21
1958 5.5
1959 4.27
1960 3.99
1961 3.28
1962 5.97
1963 7.41
1964 6.12
1965 6.02
1966 6.21
1967 5.25
1968 6.37
1969 5.67
1970 5.75
1971 5.4
1972 4.92
1973 4.51
1974 4.15
1975 3.58
1976 3.25
1977 2.87
1978 2.74
1979 2.8
1980 2.32
1981 2.67
1982 2.58
1983 2.58
1984 2.62
1985 2.66
1986 2.68
1987 2.65
1988 2.59
1989 2.49
1990 2.35
1991 2.19
1992 2.02
1993 1.87
1994 1.74
1995 1.64
1996 1.57
1997 1.53
1998 1.5
1999 1.49
2000 1.5
2001 1.51
2002 1.52
2003 1.54
2004 1.55
2005 1.57
2006 1.57
2007 1.58
2008 1.58
2009 1.59
2010 1.59
2011 1.59
2012 1.6
2013 1.6
2014 1.61
2015 1.62
2016 1.62
2017 1.63
2018 1.64