Year Years 1800 509.4 1801 509.4 1802 509.4 1803 509.4 1804 509.4 1805 509.4 1806 509.4 1807 509.4 1808 509.4 1809 509.4 1810 509.4 1811 509.4 1812 509.4 1813 509.4 1814 509.4 1815 509.4 1816 509.4 1817 509.4 1818 509.4 1819 509.4 1820 509.4 1821 509.4 1822 509.4 1823 509.4 1824 509.4 1825 509.4 1826 509.4 1827 509.4 1828 509.4 1829 509.4 1830 509.4 1831 509.4 1832 509.4 1833 509.4 1834 509.4 1835 509.4 1836 509.4 1837 509.4 1838 509.4 1839 509.4 1840 509.4 1841 509.4 1842 509.4 1843 509.4 1844 509.4 1845 509.4 1846 509.4 1847 509.4 1848 509.4 1849 509.4 1850 509.4 1851 509.4 1852 509.4 1853 509.4 1854 509.4 1855 509.4 1856 509.4 1857 509.4 1858 509.4 1859 509.4 1860 509.4 1861 509.4 1862 509.4 1863 509.4 1864 509.4 1865 509.4 1866 509.4 1867 509.4 1868 509.4 1869 509.4 1870 509.4 1871 509.4 1872 509.4 1873 509.4 1874 509.4 1875 509.4 1876 509.4 1877 509.4 1878 509.4 1879 509.4 1880 509.4 1881 509.4 1882 509.4 1883 509.4 1884 509.4 1885 509.4 1886 509.4 1887 509.4 1888 509.4 1889 509.4 1890 509.4 1891 509.4 1892 509.4 1893 509.4 1894 509.4 1895 509.3 1896 509.3 1897 509.1 1898 508.9 1899 508.6 1900 508.3 1901 507.9 1902 507.3 1903 506.7 1904 506.1 1905 505.3 1906 504.5 1907 503.6 1908 502.6 1909 501.5 1910 500.4 1911 499.2 1912 498 1913 496.8 1914 495.6 1915 494.4 1916 493.2 1917 495 1918 496.7 1919 498.4 1920 500.2 1921 501.9 1922 493.3 1923 484.9 1924 476.5 1925 467 1926 458.9 1927 451 1928 441.9 1929 434.2 1930 426.6 1931 417.9 1932 410.6 1933 403.4 1934 395 1935 388 1936 381.1 1937 373.1 1938 366.4 1939 359.8 1940 352.1 1941 344.6 1942 336.1 1943 328.8 1944 320.5 1945 312.5 1955 209.6 1956 207.5 1957 205.6 1958 203.6 1959 201.9 1960 200 1961 198.3 1962 196.5 1963 194.5 1964 192.3 1965 190 1966 187.4 1967 184.6 1968 181.3 1969 177.8 1970 173.8 1971 169.3 1972 164.1 1973 158.4 1974 152.2 1975 145.3 1976 138 1977 130.5 1978 123 1979 115.6 1980 108.6 1981 102.1 1982 96.3 1983 91 1984 86.3 1985 82.2 1986 78.5 1987 75.2 1988 72.2 1989 69.5 1990 66.8 1991 63.9 1992 61.1 1993 58.3 1994 55.5 1995 52.7 1996 50 1997 47.4 1998 44.9 1999 42.5 2000 40.3 2001 38.2 2002 36.4 2003 34.7 2004 33.1 2005 31.7 2006 30.4 2007 29.2 2008 28.1 2009 27.1 2010 26.1 2011 25.2 2012 24.3 2013 23.5