Year Years 1800 39.86 1801 39.86 1802 39.86 1803 39.86 1804 39.86 1805 39.86 1806 39.86 1807 39.86 1808 39.86 1809 39.86 1810 39.86 1811 39.86 1812 39.86 1813 39.86 1814 39.86 1815 39.86 1816 39.86 1817 39.86 1818 39.86 1819 39.86 1820 39.86 1821 39.86 1822 39.86 1823 39.86 1824 39.86 1825 39.86 1826 39.86 1827 39.86 1828 39.86 1829 39.86 1830 39.86 1831 39.86 1832 39.86 1833 39.86 1834 39.86 1835 39.86 1836 39.86 1837 39.86 1838 39.86 1839 39.86 1840 39.86 1841 39.86 1842 39.86 1843 39.86 1844 39.86 1845 39.86 1846 39.86 1847 39.86 1848 39.86 1849 39.86 1850 39.86 1851 40 1852 38.66 1853 38.63 1854 38.63 1855 34.53 1856 38.39 1857 35.46 1858 34.66 1859 30.86 1860 36.91 1861 36.44 1862 38.28 1863 38.33 1864 37.56 1865 36.37 1866 33.64 1867 39.31 1868 37.75 1869 40.47 1870 37.34 1871 32.94 1872 36.49 1873 39.2 1874 41.3 1875 38.24 1876 40.35 1877 42.03 1878 41.11 1879 41.97 1880 40.4 1881 42.88 1882 43.8 1883 42.36 1884 41.35 1885 43.31 1886 41.99 1887 45 1888 44.23 1889 44.36 1890 44.41 1891 44.26 1892 43.97 1893 45.82 1894 46.95 1895 46.66 1896 48.58 1897 49.38 1898 49.05 1899 49.37 1900 48.42 1901 48.74 1902 50.64 1903 51.54 1904 50.93 1905 52.14 1906 52.81 1907 53.57 1908 52.79 1909 54.99 1910 55.17 1911 53.2 1912 57.25 1913 57.41 1914 57.24 1915 57.26 1916 56.2 1917 55.71 1918 47.65 1919 55.02 1920 57.89 1921 59.82 1922 59.89 1923 62.11 1924 63.02 1925 63.23 1926 63.1 1927 62.71 1928 63.8 1929 62.25 1930 64.79 1931 64.41 1932 65.5 1933 66.15 1934 66.69 1935 66.61 1936 66.83 1937 67.05 1938 67.47 1939 67.8 1940 65.47 1941 65.4 1942 65.91 1943 64.5 1944 61.33 1945 55.52 1946 67.66 1947 69.61 1948 71.14 1949 70.37 1950 71.54 1951 71.6 1952 72.22 1953 71.8 1954 72.5 1955 72.62 1956 72.64 1957 73.09 1958 73.25 1959 73.29 1960 73.47 1961 73.66 1962 73.34 1963 73.46 1964 73.84 1965 73.71 1966 73.66 1967 73.93 1968 73.74 1969 73.65 1970 73.72 1971 73.83 1972 73.92 1973 74.19 1974 74.49 1975 74.65 1976 74.85 1977 75.16 1978 75.3 1979 75.59 1980 75.81 1981 75.98 1982 76.1 1983 76.22 1984 76.31 1985 76.37 1986 76.44 1987 76.68 1988 76.86 1989 76.88 1990 76.98 1991 77.12 1992 77.21 1993 77.2 1994 77.37 1995 77.48 1996 77.62 1997 77.83 1998 77.93 1999 77.96 2000 78.06 2001 78.22 2002 78.4 2003 78.67 2004 79.08 2005 79.42 2006 79.78 2007 80.11 2008 80.33 2009 80.54 2010 80.73 2011 80.92 2012 81.06 2013 81.29 2014 81.48 2015 81.62 2016 81.62 2017 81.77 2018 81.92