Year Total
1800 6.1
1801 6.1
1802 6.1
1803 6.1
1804 6.1
1805 6.1
1806 6.1
1807 6.1
1808 6.1
1809 6.1
1810 6.1
1811 6.1
1812 6.1
1813 6.1
1814 6.1
1815 6.1
1816 6.1
1817 6.1
1818 6.1
1819 6.1
1820 6.1
1821 6.1
1822 6.1
1823 6.1
1824 6.1
1825 6.1
1826 6.1
1827 6.1
1828 6.1
1829 6.1
1830 6.1
1831 6.1
1832 6.1
1833 6.1
1834 6.1
1835 6.1
1836 6.1
1837 6.1
1838 6.1
1839 6.1
1840 6.1
1841 6.1
1842 6.1
1843 6.1
1844 6.1
1845 6.1
1846 6.1
1847 6.1
1848 6.1
1849 6.1
1850 6.1
1851 6.1
1852 6.1
1853 6.1
1854 6.1
1855 6.1
1856 6.1
1857 6.1
1858 6.1
1859 6.1
1860 6.1
1861 6.1
1862 6.1
1863 6.1
1864 6.1
1865 6.1
1866 6.1
1867 6.1
1868 6.1
1869 6.1
1870 6.1
1871 6.1
1872 6.1
1873 6.1
1874 6.1
1875 6.1
1876 6.1
1877 6.1
1878 6.1
1879 6.1
1880 6.1
1881 6.1
1882 6.1
1883 6.1
1884 6.1
1885 6.1
1886 6.1
1887 6.1
1888 6.1
1889 6.1
1890 6.1
1891 6.1
1892 6.1
1893 6.1
1894 6.1
1895 6.1
1896 6.1
1897 6.1
1898 6.1
1899 6.1
1900 6.1
1901 6.1
1902 6.1
1903 6.11
1904 6.11
1905 6.11
1906 6.11
1907 6.12
1908 6.12
1909 6.12
1910 6.12
1911 6.12
1912 6.13
1913 6.13
1914 6.13
1915 6.13
1916 6.14
1917 6.14
1918 6.14
1919 6.14
1920 6.14
1921 6.14
1922 6.14
1923 6.14
1924 6.08
1925 6.03
1926 5.97
1927 5.92
1928 5.86
1929 5.91
1930 5.96
1931 6
1932 6.05
1933 6.1
1934 6.12
1935 6.14
1936 6.16
1937 6.18
1938 6.2
1939 6.16
1940 6.12
1941 6.08
1942 6.04
1943 6
1944 5.42
1945 4.84
1946 4.26
1947 3.68
1948 3.1
1949 2.53
1950 1.95
1951 2.41
1952 3.25
1953 3.92
1954 4.44
1955 4.79
1956 4.98
1957 5.03
1958 4.96
1959 4.79
1960 4.58
1961 4.36
1962 4.17
1963 4.06
1964 4.02
1965 4.06
1966 4.16
1967 4.26
1968 4.33
1969 4.35
1970 4.32
1971 4.21
1972 4.05
1973 3.85
1974 3.63
1975 3.4
1976 3.2
1977 3.03
1978 2.9
1979 2.82
1980 2.77
1981 2.75
1982 2.73
1983 2.7
1984 2.65
1985 2.58
1986 2.5
1987 2.43
1988 2.37
1989 2.32
1990 2.29
1991 2.26
1992 2.24
1993 2.2
1994 2.16
1995 2.12
1996 2.08
1997 2.04
1998 2.01
1999 2
2000 1.99
2001 1.99
2002 1.99
2003 2
2004 2
2005 2
2006 2
2007 2
2008 1.99
2009 1.99
2010 1.98
2011 1.97
2012 1.96
2013 1.95
2014 1.93
2015 1.92
2016 1.91
2017 1.9
2018 1.89