Year Years
1800 33.4
1801 33.4
1802 33.4
1803 33.4
1804 33.4
1805 33.4
1806 33.4
1807 33.4
1808 33.4
1809 33.4
1810 33.4
1811 33.4
1812 33.4
1813 33.4
1814 33.4
1815 33.4
1816 33.4
1817 33.4
1818 33.4
1819 33.4
1820 33.4
1821 33.4
1822 33.4
1823 33.4
1824 33.4
1825 33.4
1826 33.4
1827 33.4
1828 33.4
1829 33.4
1830 33.4
1831 33.4
1832 33.4
1833 33.4
1834 33.4
1835 33.4
1836 33.4
1837 33.4
1838 33.4
1839 33.4
1840 33.4
1841 33.4
1842 33.4
1843 33.4
1844 33.4
1845 33.4
1846 33.4
1847 33.4
1848 33.4
1849 33.4
1850 33.4
1851 33.4
1852 33.4
1853 33.4
1854 33.4
1855 33.4
1856 33.4
1857 33.4
1858 33.4
1859 33.4
1860 33.4
1861 33.4
1862 33.4
1863 33.4
1864 33.4
1865 33.4
1866 33.4
1867 33.4
1868 33.4
1869 33.4
1870 33.4
1871 33.4
1872 33.4
1873 33.39
1874 33.39
1875 33.39
1876 33.39
1877 33.39
1878 33.39
1879 33.38
1880 33.38
1881 33.38
1882 33.38
1883 33.38
1884 33.37
1885 33.37
1886 33.37
1887 33.37
1888 33.37
1889 33.37
1890 33.36
1891 33.36
1892 33.36
1893 33.36
1894 33.36
1895 33.35
1896 33.35
1897 33.35
1898 33.35
1899 33.35
1900 33.35
1901 33.34
1902 33.34
1903 33.34
1904 33.34
1905 33.34
1906 33.34
1907 33.33
1908 33.33
1909 33.33
1910 33.33
1911 33.33
1912 33.32
1913 33.32
1914 33.32
1915 33.32
1916 33.32
1917 33.32
1918 21.6
1919 33.31
1920 33.31
1921 33.31
1922 34.13
1923 34.96
1924 35.79
1925 36.6
1926 37.43
1927 38.25
1928 39.08
1929 39.89
1930 40.72
1931 41.54
1932 42.37
1933 43.18
1934 44.01
1935 44.83
1936 45.66
1937 46.47
1938 47.3
1939 48.12
1940 48.94
1941 49.76
1942 50.58
1943 51.41
1944 52.23
1945 53.05
1946 53.87
1947 54.69
1948 55.52
1949 56.34
1950 57.15
1951 57.65
1952 58.61
1953 59.47
1954 60.27
1955 60.97
1956 61.59
1957 62.15
1958 62.63
1959 63.06
1960 63.44
1961 63.79
1962 64.14
1963 64.49
1964 64.87
1965 65.26
1966 65.68
1967 66.09
1968 66.52
1969 66.93
1970 67.34
1971 67.55
1972 67.75
1973 68.08
1974 68.43
1975 68.76
1976 69.07
1977 69.36
1978 69.65
1979 69.92
1980 70.12
1981 70.51
1982 70.85
1983 71.32
1984 71.71
1985 71.97
1986 72.25
1987 72.36
1988 72.5
1989 72.57
1990 72.65
1991 72.67
1992 72.7
1993 72.72
1994 72.71
1995 72.68
1996 72.93
1997 73.01
1998 73.12
1999 73.24
2000 73.39
2001 73.54
2002 73.64
2003 73.69
2004 73.74
2005 73.85
2006 73.91
2007 73.96
2008 74.05
2009 74.06
2010 74.04
2011 74.19
2012 74.26
2013 74.33
2014 74.4
2015 74.5
2016 74.7
2017 74.86
2018 75.02