Year Years
1800 31.4
1801 31.4
1802 31.4
1803 31.4
1804 31.4
1805 31.4
1806 31.4
1807 31.4
1808 31.4
1809 31.4
1810 31.4
1811 31.4
1812 31.4
1813 31.4
1814 31.4
1815 31.4
1816 31.4
1817 31.4
1818 31.4
1819 31.4
1820 31.4
1821 31.4
1822 31.4
1823 31.4
1824 31.4
1825 31.4
1826 31.4
1827 31.4
1828 31.4
1829 31.4
1830 31.4
1831 31.4
1832 31.4
1833 31.4
1834 31.4
1835 31.4
1836 31.4
1837 31.4
1838 31.4
1839 31.4
1840 31.4
1841 31.4
1842 31.4
1843 31.4
1844 31.4
1845 31.4
1846 31.4
1847 31.4
1848 31.4
1849 31.4
1850 31.4
1851 31.4
1852 31.4
1853 31.4
1854 31.4
1855 31.4
1856 31.4
1857 31.4
1858 31.4
1859 31.4
1860 31.4
1861 31.4
1862 31.4
1863 31.4
1864 31.4
1865 31.4
1866 31.4
1867 31.4
1868 31.4
1869 31.4
1870 31.4
1871 31.4
1872 31.4
1873 31.41
1874 31.41
1875 31.41
1876 31.41
1877 31.41
1878 31.42
1879 31.42
1880 31.42
1881 31.42
1882 31.42
1883 31.43
1884 31.43
1885 31.43
1886 31.43
1887 31.43
1888 31.44
1889 31.44
1890 31.44
1891 31.44
1892 31.44
1893 31.45
1894 31.45
1895 31.45
1896 31.45
1897 31.45
1898 31.46
1899 31.46
1900 31.46
1901 31.46
1902 31.46
1903 31.46
1904 31.47
1905 31.47
1906 31.47
1907 31.47
1908 31.47
1909 31.48
1910 31.48
1911 31.48
1912 31.48
1913 31.48
1914 31.49
1915 31.49
1916 31.49
1917 31.49
1918 12.18
1919 31.5
1920 31.5
1921 31.5
1922 31.5
1923 31.5
1924 31.51
1925 31.51
1926 31.51
1927 31.51
1928 31.51
1929 31.52
1930 31.52
1931 31.52
1932 31.52
1933 31.52
1934 31.53
1935 31.53
1936 31.53
1937 31.53
1938 31.53
1939 31.54
1940 31.54
1941 32.75
1942 33.95
1943 35.16
1944 36.38
1945 37.59
1946 38.79
1947 40
1948 41.21
1949 42.42
1950 43.63
1951 43.92
1952 44.5
1953 45.06
1954 45.6
1955 46.11
1956 46.62
1957 47.11
1958 47.57
1959 48.03
1960 48.46
1961 48.9
1962 49.31
1963 49.73
1964 50.14
1965 50.55
1966 50.96
1967 51.38
1968 51.79
1969 52.18
1970 52.56
1971 53.36
1972 53.42
1973 53.39
1974 53.45
1975 53.53
1976 53.94
1977 54.4
1978 54.54
1979 54.76
1980 54.91
1981 55.45
1982 55.74
1983 49.79
1984 50.23
1985 50.54
1986 56.65
1987 56.87
1988 57.47
1989 57.98
1990 58.56
1991 59.06
1992 59.31
1993 59.78
1994 60.07
1995 60.41
1996 60.7
1997 61.08
1998 61.47
1999 61.86
2000 62.59
2001 63.18
2002 63.7
2003 63.76
2004 64.1
2005 64.88
2006 65.19
2007 65.59
2008 65.89
2009 66.14
2010 66.29
2011 66.48
2012 66.83
2013 67.04
2014 67.57
2015 68.01
2016 68.33
2017 68.55
2018 68.77