Year Years 1800 38.3 1801 38.3 1802 38.3 1803 38.3 1804 38.3 1805 38.3 1806 38.3 1807 38.3 1808 38.3 1809 38.3 1810 38.3 1811 38.3 1812 38.3 1813 38.3 1814 38.3 1815 38.3 1816 38.3 1817 38.3 1818 38.3 1819 38.3 1820 38.3 1821 38.3 1822 38.3 1823 38.3 1824 38.3 1825 38.3 1826 38.3 1827 38.3 1828 38.3 1829 38.3 1830 38.3 1831 38.3 1832 38.3 1833 38.3 1834 38.3 1835 38.3 1836 38.3 1837 38.3 1838 38.3 1839 38.3 1840 38.3 1841 38.3 1842 38.3 1843 38.3 1844 38.3 1845 38.3 1846 19.8 1847 24 1848 14.9 1849 14.1 1850 31.2 1851 38.3 1852 38.3 1853 38.3 1854 38.3 1855 38.3 1856 38.3 1857 38.3 1858 38.3 1859 38.3 1860 38.56 1861 38.83 1862 39.09 1863 39.36 1864 39.62 1865 39.89 1866 40.15 1867 40.41 1868 40.68 1869 40.94 1870 41.21 1871 41.47 1872 41.74 1873 42 1874 42.27 1875 42.54 1876 42.8 1877 43.07 1878 43.33 1879 43.61 1880 43.87 1881 44.13 1882 44.4 1883 44.66 1884 44.93 1885 45.2 1886 45.47 1887 45.73 1888 45.99 1889 46.26 1890 46.53 1891 46.8 1892 47.06 1893 47.33 1894 47.59 1895 47.86 1896 48.13 1897 48.39 1898 48.66 1899 48.93 1900 49.2 1901 49.46 1902 49.9 1903 50.34 1904 50.79 1905 51.23 1906 51.67 1907 52.12 1908 52.56 1909 53 1910 53.44 1911 53.89 1912 54.14 1913 54.4 1914 54.65 1915 54.91 1916 55.17 1917 55.42 1918 49.77 1919 55.94 1920 56.19 1921 56.44 1922 56.7 1923 56.96 1924 57.21 1925 57.47 1926 57.73 1927 57.86 1928 57.99 1929 58.12 1930 58.26 1931 58.39 1932 58.52 1933 58.65 1934 58.79 1935 58.92 1936 59.05 1937 59.27 1938 59.5 1939 59.72 1940 59.94 1941 60.17 1942 60.45 1943 60.73 1944 61.02 1945 61.3 1946 61.58 1947 62.64 1948 63.7 1949 64.76 1950 65.81 1951 64.98 1952 67.41 1953 68.18 1954 68.29 1955 68.29 1956 69.24 1957 69.29 1958 69.6 1959 69.73 1960 70.48 1961 69.94 1962 70.24 1963 70.49 1964 70.75 1965 70.95 1966 70.46 1967 71.51 1968 71.2 1969 71.12 1970 71.17 1971 71.31 1972 71.25 1973 71.25 1974 71.39 1975 71.68 1976 71.99 1977 72.13 1978 72.15 1979 72.31 1980 72.66 1981 72.97 1982 73.17 1983 73.3 1984 73.57 1985 73.85 1986 74.07 1987 74.38 1988 74.53 1989 74.69 1990 74.91 1991 75.16 1992 75.35 1993 75.54 1994 75.73 1995 75.8 1996 76 1997 76.08 1998 76.22 1999 76.36 2000 76.65 2001 77.14 2002 77.65 2003 78.12 2004 78.51 2005 78.91 2006 79.25 2007 79.58 2008 79.75 2009 79.94 2010 80.38 2011 80.54 2012 80.76 2013 80.96 2014 81.1 2015 81.12 2016 81.15 2017 81.32 2018 81.49