Year Years 1800 439.8 1801 439.8 1802 439.8 1803 439.8 1804 439.8 1805 439.8 1806 439.8 1807 439.8 1808 439.8 1809 439.8 1810 439.8 1811 439.8 1812 439.8 1813 439.8 1814 439.8 1815 439.8 1816 439.8 1817 439.8 1818 439.8 1819 439.8 1820 439.8 1821 439.8 1822 439.8 1823 439.8 1824 439.8 1825 439.8 1826 439.8 1827 439.8 1828 439.8 1829 439.8 1830 439.8 1831 439.8 1832 439.8 1833 439.8 1834 439.8 1835 439.8 1836 439.8 1837 439.8 1838 439.8 1839 439.8 1840 439.8 1841 439.8 1842 439.8 1843 439.8 1844 439.8 1845 439.8 1846 439.8 1847 439.8 1848 439.8 1849 439.8 1850 439.8 1851 439.8 1852 439.8 1853 439.8 1854 439.8 1855 439.8 1856 439.8 1857 439.8 1858 439.8 1859 439.8 1860 439.8 1861 439.8 1862 439.8 1863 439.8 1864 439.8 1865 439.8 1866 439.8 1867 439.8 1868 439.8 1869 439.8 1870 439.8 1871 439.8 1872 439.8 1873 439.8 1874 439.8 1875 439.8 1876 439.8 1877 439.8 1878 439.8 1879 439.8 1880 439.8 1881 439.8 1882 439.8 1883 439.8 1884 439.8 1885 439.8 1886 439.8 1887 439.8 1888 439.8 1889 439.8 1890 439.8 1891 439.8 1892 439.8 1893 439.8 1894 439.8 1895 439.8 1896 439.7 1897 439.6 1898 439.4 1899 439.1 1900 438.8 1901 438.5 1902 438 1903 437.5 1904 436.9 1905 436.3 1906 435.5 1907 434.8 1908 433.9 1909 433 1910 432 1911 431 1912 430 1913 429 1914 427.9 1915 426.9 1916 425.9 1917 424.8 1918 423.8 1919 422.8 1920 421.7 1921 420.7 1922 419.7 1923 418.6 1924 417.6 1925 416.6 1926 415.5 1927 414.5 1928 413.5 1929 412.4 1930 411.4 1931 410.4 1932 409.4 1933 408.3 1934 407.3 1935 406.2 1936 396.6 1937 387.2 1938 376.8 1939 367.8 1940 358.8 1941 350.1 1942 340.4 1943 332 1944 323.7 1945 315.6 1946 306.5 1955 306.6 1956 281.9 1957 259.2 1958 238 1959 218.5 1960 200.3 1961 183.1 1962 167.3 1963 152.5 1964 138.7 1965 126.1 1966 114.3 1967 103.5 1968 93.7 1969 84.6 1970 76.4 1971 69 1972 62.5 1973 56.6 1974 51.6 1975 47.2 1976 43.4 1977 40.1 1978 37.1 1979 34.5 1980 32.3 1981 30.3 1982 28.7 1983 27.2 1984 26 1985 25 1986 24.2 1987 23.7 1988 23.4 1989 23.2 1990 23 1991 22.6 1992 21.9 1993 20.9 1994 19.6 1995 18.1 1996 16.6 1997 15.3 1998 14.2 1999 13.3 2000 12.7 2001 12.2 2002 11.9 2003 11.6 2004 11.3 2005 10.9 2006 10.4 2007 9.9 2008 9.2 2009 8.5 2010 7.8 2011 7.2 2012 6.6 2013 6.1