Year Years 1800 507.9 1801 507.9 1802 507.9 1803 507.9 1804 507.9 1805 507.9 1806 507.9 1807 507.9 1808 507.9 1809 507.9 1810 507.9 1811 507.9 1812 507.9 1813 507.9 1814 507.9 1815 507.9 1816 507.9 1817 507.9 1818 507.9 1819 507.9 1820 507.9 1821 507.9 1822 507.9 1823 507.9 1824 507.9 1825 507.9 1826 507.9 1827 507.9 1828 507.9 1829 507.9 1830 507.9 1831 507.9 1832 507.9 1833 507.9 1834 507.9 1835 507.9 1836 507.9 1837 507.9 1838 507.9 1839 507.9 1840 507.9 1841 507.9 1842 507.9 1843 507.9 1844 507.9 1845 507.9 1846 507.9 1847 507.9 1848 507.9 1849 507.9 1850 507.9 1851 507.9 1852 507.9 1853 507.9 1854 507.9 1855 507.9 1856 507.9 1857 507.9 1858 507.9 1859 507.9 1860 507.9 1861 507.9 1862 507.9 1863 507.9 1864 507.9 1865 507.9 1866 507.9 1867 507.9 1868 507.9 1869 507.9 1870 507.9 1871 507.9 1872 507.9 1873 507.9 1874 507.9 1875 507.9 1876 507.9 1877 507.9 1878 507.9 1879 507.9 1880 507.9 1881 507.9 1882 507.9 1883 507.9 1884 507.9 1885 507.9 1886 507.9 1887 507.9 1888 507.9 1889 507.9 1890 507.9 1891 507.9 1892 507.9 1893 507.9 1894 507.9 1895 507.8 1896 507.8 1897 507.6 1898 507.4 1899 507.1 1900 506.8 1901 506.4 1902 505.8 1903 505.2 1904 504.6 1905 503.8 1906 503 1907 502.1 1908 501.1 1909 500 1910 498.9 1911 497.7 1912 496.6 1913 495.4 1914 494.2 1915 493 1916 491.8 1917 490.6 1918 489.4 1919 488.2 1920 487 1921 485.8 1922 484.6 1923 487.8 1924 490.9 1925 494.1 1926 498.7 1927 501.9 1928 496.2 1929 492.1 1930 486.5 1931 482.4 1932 478.3 1933 472.9 1934 468.9 1935 463.6 1936 459.7 1937 454.4 1938 449.2 1939 444.1 1940 439 1950 319.8 1951 305.4 1952 291.6 1953 278 1954 264.8 1955 252.2 1956 240.3 1957 228.9 1958 218.2 1959 208.2 1960 199 1961 190.8 1962 183.4 1963 176.8 1964 171.2 1965 166.5 1966 162.4 1967 158.6 1968 155 1969 151.5 1970 147.9 1971 144.2 1972 140.5 1973 136.7 1974 132.7 1975 128.6 1976 124.4 1977 120.2 1978 116.1 1979 112.2 1980 108.5 1981 105.2 1982 102.3 1983 99.8 1984 97.7 1985 96.3 1986 95.5 1987 95.4 1988 95.9 1989 97 1990 98.7 1991 101 1992 103.7 1993 106.5 1994 109.2 1995 111.4 1996 112.9 1997 113.6 1998 113.3 1999 112.4 2000 110.9 2001 108.8 2002 106.5 2003 103.8 2004 101 2005 97.8 2006 94.1 2007 90.5 2008 86.4 2009 83.1 2010 79.5 2011 75.8 2012 73.1 2013 70.7