Year Years 1800 471.4 1801 471.4 1802 471.4 1803 471.4 1804 471.4 1805 471.4 1806 471.4 1807 471.4 1808 471.4 1809 471.4 1810 471.4 1811 471.4 1812 471.4 1813 471.4 1814 471.4 1815 471.4 1816 471.4 1817 471.4 1818 471.4 1819 471.4 1820 471.4 1821 471.4 1822 471.4 1823 471.4 1824 471.4 1825 471.4 1826 471.4 1827 471.4 1828 471.4 1829 471.4 1830 471.4 1831 471.4 1832 471.4 1833 471.4 1834 471.4 1835 471.4 1836 471.4 1837 471.4 1838 471.4 1839 471.4 1840 471.4 1841 471.4 1842 471.4 1843 471.4 1844 471.4 1845 471.4 1846 471.4 1847 471.4 1848 471.4 1849 471.4 1850 471.4 1851 471.4 1852 471.4 1853 471.4 1854 471.4 1855 471.4 1856 471.4 1857 471.4 1858 471.4 1859 471.4 1860 471.4 1861 471.4 1862 471.4 1863 471.4 1864 471.4 1865 471.4 1866 471.4 1867 471.4 1868 471.4 1869 471.4 1870 471.4 1871 471.4 1872 471.4 1873 471.4 1874 471.4 1875 471.4 1876 471.4 1877 471.4 1878 471.4 1879 471.4 1880 471.4 1881 471.4 1882 471.4 1883 471.4 1884 471.4 1885 471.4 1886 471.4 1887 471.4 1888 471.4 1889 471.4 1890 471.4 1891 471.4 1892 471.4 1893 471.4 1894 471.4 1895 471.3 1896 471.2 1897 471.1 1898 470.9 1899 470.7 1900 470.4 1901 469.9 1902 469.5 1903 468.9 1904 468.3 1905 467.6 1906 466.8 1907 466 1908 465.1 1909 464.1 1910 463 1911 462 1912 460.9 1913 459.8 1914 458.7 1915 457.6 1916 456.4 1917 455.3 1918 454.2 1919 453.1 1920 452 1921 450.9 1922 449.8 1923 448.7 1924 447.6 1925 446.5 1926 438.8 1927 431.1 1928 422.4 1929 414.9 1930 407.7 1931 400.5 1932 392.2 1933 385.2 1934 378.3 1935 371.5 1936 363.7 1937 357.1 1938 350.6 1939 344.2 1940 336.7 1950 256.1 1951 249.9 1952 243.8 1953 238.3 1954 233 1955 228.2 1956 223.7 1957 219.4 1958 215.9 1959 212.8 1960 210.3 1961 208.3 1962 206.7 1963 205.8 1964 205.1 1965 204.4 1966 204.1 1967 203.7 1968 203.2 1969 202.3 1970 201.1 1971 199.4 1972 197.1 1973 193.9 1974 190 1975 185.5 1976 180.9 1977 176.5 1978 172.6 1979 169.7 1980 167.7 1981 166 1982 164.4 1983 162.3 1984 159.3 1985 155.3 1986 150.4 1987 144.8 1988 139 1989 133.3 1990 128.2 1991 123.9 1992 120.5 1993 117.8 1994 115.8 1995 114 1996 112.1 1997 110 1998 107.4 1999 104.5 2000 101.3 2001 98 2002 94.9 2003 92.2 2004 90.1 2005 88.3 2006 87 2007 86 2008 85.2 2009 84.2 2010 83.2 2011 81.7 2012 80.2 2013 78.4