Year Total
1800 6.05
1801 6.05
1802 6.05
1803 6.06
1804 6.06
1805 6.06
1806 6.06
1807 6.07
1808 6.07
1809 6.07
1810 6.07
1811 6.07
1812 6.08
1813 6.08
1814 6.08
1815 6.08
1816 6.08
1817 6.09
1818 6.09
1819 6.09
1820 6.09
1821 6.1
1822 6.1
1823 6.1
1824 6.1
1825 6.1
1826 6.11
1827 6.11
1828 6.11
1829 6.11
1830 6.12
1831 6.12
1832 6.12
1833 6.12
1834 6.12
1835 6.13
1836 6.13
1837 6.13
1838 6.13
1839 6.13
1840 6.14
1841 6.14
1842 6.14
1843 6.14
1844 6.15
1845 6.15
1846 6.15
1847 6.15
1848 6.15
1849 6.16
1850 6.16
1851 6.16
1852 6.16
1853 6.16
1854 6.17
1855 6.17
1856 6.17
1857 6.17
1858 6.18
1859 6.18
1860 6.18
1861 6.18
1862 6.18
1863 6.19
1864 6.19
1865 6.19
1866 6.19
1867 6.2
1868 6.2
1869 6.2
1870 6.2
1871 6.2
1872 6.21
1873 6.21
1874 6.21
1875 6.21
1876 6.21
1877 6.22
1878 6.22
1879 6.22
1880 6.22
1881 6.23
1882 6.23
1883 6.23
1884 6.23
1885 6.23
1886 6.24
1887 6.24
1888 6.24
1889 6.24
1890 6.25
1891 6.25
1892 6.25
1893 6.25
1894 6.25
1895 6.26
1896 6.26
1897 6.26
1898 6.26
1899 6.26
1900 6.27
1901 6.27
1902 6.27
1903 6.27
1904 6.28
1905 6.28
1906 6.28
1907 6.28
1908 6.28
1909 6.29
1910 6.29
1911 6.29
1912 6.29
1913 6.24
1914 6.18
1915 6.12
1916 6.06
1917 6
1918 6.08
1919 6.15
1920 6.23
1921 6.3
1922 6.38
1923 6.37
1924 6.37
1925 6.36
1926 6.36
1927 6.35
1928 6.29
1929 6.23
1930 6.17
1931 6.11
1932 6.05
1933 6.05
1934 6.04
1935 6.04
1936 6.04
1937 6.03
1938 6.09
1939 6.14
1940 6.2
1941 6.25
1942 6.31
1943 6.33
1944 6.35
1945 6.37
1946 6.39
1947 6.41
1948 6.76
1949 7.12
1950 7.47
1951 7.48
1952 7.5
1953 7.51
1954 7.51
1955 7.51
1956 7.51
1957 7.5
1958 7.49
1959 7.47
1960 7.46
1961 7.45
1962 7.44
1963 7.44
1964 7.44
1965 7.44
1966 7.44
1967 7.42
1968 7.38
1969 7.33
1970 7.27
1971 7.2
1972 7.11
1973 7.03
1974 6.94
1975 6.84
1976 6.75
1977 6.65
1978 6.54
1979 6.43
1980 6.31
1981 6.19
1982 6.06
1983 5.93
1984 5.8
1985 5.67
1986 5.55
1987 5.44
1988 5.33
1989 5.23
1990 5.14
1991 5.05
1992 4.95
1993 4.85
1994 4.75
1995 4.64
1996 4.53
1997 4.41
1998 4.29
1999 4.17
2000 4.06
2001 3.94
2002 3.82
2003 3.69
2004 3.57
2005 3.45
2006 3.33
2007 3.2
2008 3.09
2009 2.98
2010 2.87
2011 2.78
2012 2.69
2013 2.62
2014 2.56
2015 2.51
2016 2.46
2017 2.42
2018 2.39