Year Years
1800 35.6
1801 35.6
1802 35.6
1803 35.6
1804 35.6
1805 35.6
1806 35.6
1807 35.6
1808 35.6
1809 35.6
1810 35.6
1811 35.6
1812 35.6
1813 35.6
1814 35.6
1815 35.6
1816 35.6
1817 35.6
1818 35.6
1819 35.6
1820 35.6
1821 35.6
1822 35.6
1823 35.6
1824 35.6
1825 35.6
1826 35.6
1827 35.6
1828 35.6
1829 35.6
1830 35.6
1831 35.6
1832 35.6
1833 35.6
1834 35.6
1835 35.6
1836 35.6
1837 35.6
1838 35.6
1839 35.6
1840 35.6
1841 35.6
1842 35.6
1843 35.6
1844 35.6
1845 35.6
1846 35.6
1847 35.6
1848 35.6
1849 35.6
1850 35.6
1851 35.6
1852 35.6
1853 35.6
1854 35.6
1855 35.6
1856 35.6
1857 35.6
1858 35.6
1859 35.6
1860 35.6
1861 35.6
1862 35.6
1863 35.6
1864 35.6
1865 35.6
1866 35.6
1867 35.6
1868 35.6
1869 35.6
1870 35.6
1871 35.6
1872 35.6
1873 35.6
1874 35.6
1875 35.61
1876 35.61
1877 35.61
1878 35.61
1879 35.61
1880 35.61
1881 35.61
1882 35.61
1883 35.62
1884 35.62
1885 35.62
1886 35.62
1887 35.62
1888 35.62
1889 35.62
1890 35.62
1891 35.63
1892 35.63
1893 35.63
1894 35.63
1895 35.63
1896 35.63
1897 35.63
1898 35.63
1899 35.63
1900 35.64
1901 35.64
1902 35.64
1903 35.64
1904 35.64
1905 35.64
1906 35.64
1907 35.64
1908 35.65
1909 35.65
1910 35.65
1911 35.65
1912 35.65
1913 35.65
1914 35.65
1915 35.65
1916 35.65
1917 35.66
1918 20.42
1919 35.66
1920 35.66
1921 35.66
1922 35.66
1923 35.66
1924 35.66
1925 35.67
1926 36.73
1927 37.78
1928 38.85
1929 39.9
1930 40.96
1931 42.02
1932 43.08
1933 44.13
1934 45.2
1935 46.25
1936 47.31
1937 48.37
1938 49.43
1939 50.49
1940 51.55
1941 48.06
1942 49.99
1943 51.18
1944 52.55
1945 53.95
1946 53.83
1947 56.17
1948 56.91
1949 55.53
1950 58.69
1951 58.88
1952 59.98
1953 61.29
1954 62.44
1955 61.61
1956 61.42
1957 61.69
1958 64
1959 63.18
1960 64.44
1961 63.06
1962 64.59
1963 65.22
1964 65.45
1965 66.4
1966 65.91
1967 66.82
1968 67.13
1969 66.74
1970 67.4
1971 67.67
1972 68.37
1973 68.73
1974 69.11
1975 69.74
1976 70.08
1977 70.31
1978 70.79
1979 71.25
1980 71.62
1981 71.97
1982 72.4
1983 72.63
1984 72.9
1985 73.19
1986 73.49
1987 73.77
1988 73.97
1989 74.19
1990 74.31
1991 74.48
1992 74.77
1993 74.95
1994 75.22
1995 75.31
1996 75.45
1997 75.79
1998 76.05
1999 76.28
2000 76.68
2001 77.03
2002 77.32
2003 77.61
2004 78.05
2005 78.33
2006 78.75
2007 79.01
2008 79.29
2009 79.56
2010 79.84
2011 80.13
2012 80.3
2013 80.52
2014 80.74
2015 80.81
2016 80.9
2017 81.1
2018 81.3