Year Years 1800 420 1801 420 1802 420 1803 420 1804 420 1805 420 1806 420 1807 420 1808 420 1809 420 1810 420 1811 420 1812 420 1813 420 1814 420 1815 420 1816 420 1817 420 1818 420 1819 420 1820 420 1821 420 1822 420 1823 420 1824 420 1825 420 1826 420 1827 420 1828 420 1829 420 1830 420 1831 420 1832 420 1833 420 1834 420 1835 420 1836 420 1837 420 1838 420 1839 420 1840 420 1841 420 1842 420 1843 420 1844 420 1845 420 1846 420 1847 420 1848 420 1849 420 1850 420 1851 420 1852 420 1853 420 1854 420 1855 420 1856 420 1857 420 1858 420 1859 420 1860 420 1861 420 1862 420 1863 420 1864 420 1865 420 1866 420 1867 420 1868 420 1869 420 1870 420 1871 420 1872 420 1873 420 1874 420 1875 420 1876 420 1877 420 1878 420 1879 420 1880 420 1881 420 1882 420 1883 420 1884 420 1885 420 1886 420 1887 420 1888 420 1889 420 1890 420 1891 420 1892 420 1893 420 1894 420 1895 420 1896 419.9 1897 419.8 1898 419.7 1899 419.4 1900 419.1 1901 418.8 1902 418.3 1903 417.9 1904 417.3 1905 416.7 1906 416 1907 415.2 1908 414.4 1909 413.5 1910 412.6 1911 411.6 1912 410.7 1913 409.7 1914 408.7 1915 407.7 1916 406.7 1917 405.8 1918 404.8 1919 403.8 1920 402.8 1921 401.8 1922 400.8 1923 399.8 1924 398.9 1925 397.9 1926 396.9 1927 395.9 1928 394.9 1929 393.9 1930 392.9 1931 391.9 1932 391 1933 390 1934 389 1935 388 1936 387 1937 386 1938 385.1 1939 384.1 1940 383.1 1941 382.1 1942 381.1 1943 380.1 1944 379.1 1945 378.1 1946 353.3 1947 328.5 1948 305.9 1949 283.3 1950 262.6 1978 177.8 1979 171.1 1980 164.6 1981 158.4 1982 152.5 1983 146.6 1984 140.9 1985 135.2 1986 129.6 1987 123.9 1988 118.4 1989 113 1990 107.9 1991 103 1992 98.4 1993 93.9 1994 89.6 1995 85.4 1996 81.2 1997 77 1998 72.8 1999 68.7 2000 64.6 2001 60.5 2002 56.7 2003 53 2004 49.6 2005 46.4 2006 43.6 2007 41.1 2008 39 2009 37.2 2010 35.7 2011 34.2 2012 32.9 2013 31.8