Year Years
1800 34.4
1801 34.4
1802 34.4
1803 34.4
1804 34.4
1805 34.4
1806 34.4
1807 34.4
1808 34.4
1809 34.4
1810 34.4
1811 34.4
1812 34.4
1813 34.4
1814 34.4
1815 34.4
1816 34.4
1817 34.4
1818 34.4
1819 34.4
1820 34.4
1821 34.4
1822 34.4
1823 34.4
1824 34.4
1825 34.4
1826 34.4
1827 34.4
1828 34.4
1829 34.4
1830 34.4
1831 34.4
1832 34.4
1833 34.4
1834 34.4
1835 34.4
1836 34.4
1837 34.4
1838 34.4
1839 34.4
1840 34.4
1841 34.4
1842 34.4
1843 34.4
1844 34.4
1845 34.4
1846 34.4
1847 34.4
1848 34.4
1849 34.4
1850 34.4
1851 34.4
1852 34.4
1853 34.4
1854 34.4
1855 34.4
1856 34.4
1857 34.4
1858 34.4
1859 34.4
1860 34.4
1861 34.4
1862 34.4
1863 34.4
1864 34.4
1865 34.4
1866 34.4
1867 34.4
1868 34.4
1869 34.4
1870 34.4
1871 34.45
1872 34.51
1873 34.56
1874 34.62
1875 34.67
1876 34.73
1877 34.78
1878 34.84
1879 34.89
1880 34.95
1881 35
1882 35.23
1883 35.46
1884 35.69
1885 35.91
1886 36.14
1887 36.37
1888 36.6
1889 36.83
1890 37.06
1891 37.29
1892 37.76
1893 38.23
1894 38.7
1895 39.17
1896 39.64
1897 40.11
1898 40.58
1899 41.05
1900 41.52
1901 41.99
1902 41.04
1903 40.09
1904 40.72
1905 41.34
1906 41.97
1907 42.58
1908 43.21
1909 43.83
1910 44.46
1911 45.08
1912 45.65
1913 46.22
1914 46.78
1915 47.35
1916 47.92
1917 48.49
1918 32.41
1919 49.62
1920 50.19
1921 50.75
1922 51.31
1923 51.88
1924 52.45
1925 53.02
1926 53.58
1927 54.15
1928 54.72
1929 55.29
1930 55.85
1931 56.42
1932 56.73
1933 57.03
1934 57.32
1935 57.63
1936 57.93
1937 58.23
1938 58.54
1939 58.06
1940 57.76
1941 56.46
1942 54.06
1943 50.16
1944 39.07
1945 31.38
1946 55.96
1947 61.26
1948 63.19
1949 63.38
1950 64.83
1951 65.21
1952 66.75
1953 67.24
1954 67.27
1955 67.54
1956 67.66
1957 67.42
1958 68.43
1959 68.36
1960 68.72
1961 69.69
1962 69.48
1963 69.61
1964 70.1
1965 69.89
1966 70.19
1967 70.07
1968 70.22
1969 69.99
1970 70.04
1971 70.17
1972 70.42
1973 70.78
1974 70.96
1975 71.24
1976 71.64
1977 71.95
1978 72.14
1979 72.35
1980 72.51
1981 72.76
1982 72.96
1983 73.2
1984 73.55
1985 73.87
1986 74.27
1987 74.64
1988 75.01
1989 75.23
1990 75.51
1991 75.71
1992 75.9
1993 76.14
1994 76.4
1995 76.68
1996 76.95
1997 77.25
1998 77.53
1999 77.8
2000 78.12
2001 78.47
2002 78.71
2003 78.91
2004 79.23
2005 79.48
2006 79.77
2007 80
2008 80.19
2009 80.3
2010 80.5
2011 80.72
2012 80.87
2013 81.07
2014 81.31
2015 81.4
2016 81.48
2017 81.66
2018 81.84