Year Years 1800 35.8 1801 35.84 1802 35.89 1803 35.93 1804 35.98 1805 36.02 1806 36.06 1807 36.11 1808 36.15 1809 36.2 1810 36.24 1811 36.28 1812 36.33 1813 36.37 1814 36.42 1815 36.46 1816 36.5 1817 36.55 1818 36.59 1819 36.64 1820 36.68 1821 36.72 1822 36.77 1823 36.81 1824 36.86 1825 36.9 1826 36.94 1827 36.99 1828 37.03 1829 37.08 1830 37.12 1831 37.16 1832 37.21 1833 37.25 1834 37.3 1835 37.34 1836 37.38 1837 37.43 1838 37.47 1839 37.52 1840 37.56 1841 37.6 1842 37.65 1843 37.69 1844 37.74 1845 37.78 1846 37.82 1847 37.87 1848 37.91 1849 37.96 1850 38 1851 38.04 1852 38.09 1853 38.13 1854 38.18 1855 38.22 1856 38.26 1857 38.31 1858 38.35 1859 38.4 1860 38.44 1861 38.48 1862 38.53 1863 38.57 1864 38.62 1865 38.66 1866 38.7 1867 38.75 1868 38.79 1869 38.84 1870 38.88 1871 38.92 1872 38.97 1873 39.01 1874 39.06 1875 39.09 1876 39.13 1877 39.18 1878 39.22 1879 39.27 1880 39.31 1881 39.35 1882 39.4 1883 39.43 1884 39.48 1885 39.52 1886 39.56 1887 39.61 1888 39.65 1889 39.7 1890 39.73 1891 39.77 1892 39.82 1893 39.86 1894 39.91 1895 39.95 1896 39.99 1897 40.04 1898 40.07 1899 40.12 1900 40.16 1901 41.31 1902 42.46 1903 42.73 1904 42.98 1905 43.25 1906 43.32 1907 43.39 1908 43.47 1909 43.54 1910 43.6 1911 43.67 1912 43.75 1913 43.82 1914 43.89 1915 43.96 1916 44.03 1917 44.1 1918 33.67 1919 44.24 1920 44.31 1921 44.39 1922 44.46 1923 44.53 1924 44.75 1925 44.99 1926 45.22 1927 45.97 1928 46.71 1929 47.46 1930 48.21 1931 48.71 1932 49.2 1933 49.7 1934 50.2 1935 50.7 1936 51.19 1937 51.69 1938 51.92 1939 52.15 1940 52.36 1941 52.59 1942 51.88 1943 51.38 1944 49.88 1945 51.88 1946 53.47 1947 53.95 1948 55.65 1949 57.78 1950 61.23 1951 60.47 1952 59.45 1953 63.97 1954 64.23 1955 64.64 1956 65.03 1957 66.43 1958 68.52 1959 66.38 1960 68.98 1961 70.02 1962 69.31 1963 70.13 1964 70.93 1965 71.09 1966 71.01 1967 70.2 1968 71.03 1969 70.21 1970 71.04 1971 70.99 1972 71.02 1973 71.21 1974 71.16 1975 71.25 1976 71.31 1977 71.07 1978 71.22 1979 71.29 1980 71.25 1981 71.41 1982 71.27 1983 71.41 1984 71.38 1985 71.34 1986 71.53 1987 71.55 1988 71.6 1989 71.59 1990 71.48 1991 71.35 1992 71.26 1993 71.22 1994 70.94 1995 71.02 1996 70.88 1997 70.63 1998 71.13 1999 71.51 2000 71.75 2001 71.99 2002 72.25 2003 72.46 2004 72.56 2005 72.66 2006 72.79 2007 73.06 2008 73.35 2009 73.61 2010 73.86 2011 74.31 2012 74.69 2013 74.9 2014 74.97 2015 75.03 2016 75.07 2017 75.2 2018 75.32