Year Years 1800 540.4 1801 540.4 1802 540.4 1803 540.4 1804 540.4 1805 540.4 1806 540.4 1807 540.4 1808 540.4 1809 540.4 1810 540.4 1811 540.4 1812 540.4 1813 540.4 1814 540.4 1815 540.4 1816 540.4 1817 540.4 1818 540.4 1819 540.4 1820 540.4 1821 540.4 1822 540.4 1823 540.4 1824 540.4 1825 540.4 1826 540.4 1827 540.4 1828 540.4 1829 540.4 1830 540.4 1831 540.4 1832 540.4 1833 540.4 1834 540.4 1835 540.4 1836 540.4 1837 540.4 1838 540.4 1839 540.4 1840 540.4 1841 540.4 1842 540.4 1843 540.4 1844 540.4 1845 540.4 1846 540.4 1847 540.4 1848 540.4 1849 540.4 1850 540.4 1851 540.4 1852 540.4 1853 540.4 1854 540.4 1855 540.4 1856 540.4 1857 540.4 1858 540.4 1859 540.4 1860 540.4 1861 540.4 1862 540.4 1863 540.4 1864 540.4 1865 540.4 1866 540.4 1867 540.4 1868 540.4 1869 540.4 1870 540.4 1871 540.4 1872 540.4 1873 540.4 1874 540.4 1875 540.4 1876 540.4 1877 540.4 1878 540.4 1879 540.4 1880 540.4 1881 540.4 1882 540.4 1883 540.4 1884 540.4 1885 540.4 1886 540.4 1887 540.4 1888 540.4 1889 540.4 1890 540.4 1891 540.4 1892 540.4 1893 540.4 1894 540.4 1895 540.4 1896 540.3 1897 540.2 1898 539.9 1899 539.6 1900 539.3 1901 538.8 1902 538.2 1903 537.6 1904 536.9 1905 536.1 1906 535.2 1907 534.2 1908 533.2 1909 532 1910 530.9 1911 529.6 1912 528.4 1913 527.1 1914 525.9 1915 524.6 1916 523.3 1917 522 1918 520.8 1919 519.5 1920 518.2 1921 517 1922 515.7 1923 514.4 1924 513.2 1925 511.9 1926 510.6 1927 509.4 1928 508.1 1929 506.8 1930 505.6 1931 504.3 1932 503 1933 501.8 1934 500.5 1935 499.2 1936 497.9 1937 496.7 1938 495.4 1939 494.1 1940 492.9 1941 491.6 1942 490.3 1943 489.1 1944 487.8 1945 486.5 1946 485.3 1947 484 1948 482.7 1949 481.5 1950 480.2 1951 471.9 1952 481.9 1953 470.4 1954 459.3 1955 448.6 1956 438.4 1957 428.8 1958 419.9 1959 411.6 1960 403.5 1961 396.2 1962 389.2 1963 383.2 1964 376.6 1965 369.9 1966 362.3 1967 353.7 1968 344.2 1969 333.8 1970 323.3 1971 312.6 1972 301.9 1973 291.2 1974 280.4 1975 269.1 1976 257.1 1977 244.6 1978 231.8 1979 219 1980 206.4 1981 194 1982 182.3 1983 171.3 1984 161.4 1985 152.8 1986 145.4 1987 139.1 1988 133.6 1989 128.9 1990 124.8 1991 121.3 1992 118.3 1993 115.7 1994 113.3 1995 111.1 1996 109 1997 106.6 1998 103.5 1999 99.8 2000 95.7 2001 91.5 2002 87.1 2003 82.9 2004 78.9 2005 75.1 2006 71.5 2007 68 2008 64.8 2009 61.7 2010 58.8 2011 56.1 2012 53.6 2013 51.3