Year Years
1800 23.39
1801 23.39
1802 23.39
1803 23.39
1804 23.39
1805 23.39
1806 23.39
1807 23.39
1808 23.39
1809 23.39
1810 23.39
1811 23.39
1812 23.39
1813 23.39
1814 23.39
1815 23.39
1816 23.39
1817 23.39
1818 23.39
1819 23.39
1820 23.39
1821 23.39
1822 23.39
1823 23.39
1824 23.39
1825 23.39
1826 23.39
1827 23.39
1828 23.39
1829 23.39
1830 23.39
1831 23.39
1832 23.39
1833 23.39
1834 23.39
1835 23.39
1836 23.39
1837 23.39
1838 23.39
1839 23.39
1840 23.39
1841 23.39
1842 23.39
1843 23.39
1844 23.39
1845 23.39
1846 23.39
1847 23.39
1848 23.39
1849 23.39
1850 23.39
1851 23.39
1852 23.39
1853 23.39
1854 23.39
1855 23.39
1856 23.39
1857 23.39
1858 23.39
1859 23.39
1860 23.39
1861 23.39
1862 23.39
1863 23.39
1864 23.39
1865 23.39
1866 23.39
1867 23.39
1868 23.39
1869 23.39
1870 23.39
1871 23.39
1872 23.4
1873 23.4
1874 23.41
1875 23.41
1876 23.42
1877 23.42
1878 23.43
1879 23.43
1880 23.44
1881 23.44
1882 23.44
1883 23.45
1884 23.45
1885 23.46
1886 23.46
1887 23.47
1888 23.47
1889 23.48
1890 23.48
1891 23.49
1892 23.49
1893 23.5
1894 23.5
1895 23.5
1896 23.51
1897 23.51
1898 23.52
1899 23.52
1900 23.53
1901 23.53
1902 23.54
1903 23.54
1904 23.55
1905 23.55
1906 23.55
1907 23.56
1908 23.56
1909 23.57
1910 23.57
1911 23.58
1912 23.58
1913 23.59
1914 23.59
1915 23.6
1916 23.6
1917 23.61
1918 19.57
1919 23.61
1920 23.62
1921 23.62
1922 23.63
1923 23.63
1924 23.64
1925 23.64
1926 23.65
1927 23.65
1928 23.66
1929 23.66
1930 23.66
1931 23.67
1932 23.67
1933 23.68
1934 23.68
1935 23.69
1936 23.69
1937 23.7
1938 23.7
1939 23.71
1940 23.71
1941 23.72
1942 23.72
1943 23.72
1944 23.73
1945 23.73
1946 23.74
1947 23.74
1948 23.75
1949 23.75
1950 23.76
1951 24.24
1952 25.21
1953 26.18
1954 27.14
1955 28.11
1956 29.08
1957 30.05
1958 31.03
1959 31.99
1960 32.96
1961 33.91
1962 34.87
1963 35.8
1964 36.73
1965 37.65
1966 38.54
1967 39.41
1968 40.28
1969 41.13
1970 41.99
1971 44.48
1972 45.44
1973 46.58
1974 47.62
1975 48.58
1976 49.66
1977 50.7
1978 51.53
1979 52.44
1980 53.15
1981 53.9
1982 54.12
1983 55.4
1984 56.04
1985 56.56
1986 54.58
1987 57.48
1988 57.89
1989 58.27
1990 58.71
1991 59.1
1992 59.45
1993 59.79
1994 59.89
1995 60.46
1996 60.8
1997 61.25
1998 61.66
1999 62.15
2000 62.61
2001 63.07
2002 63.53
2003 63.99
2004 64.51
2005 64.97
2006 65.52
2007 65.84
2008 66.4
2009 67.03
2010 67.51
2011 67.68
2012 67.91
2013 68.36
2014 68.44
2015 67.19
2016 66.72
2017 66.93
2018 67.14