Year Years 1800 456.1 1801 456.1 1802 456.1 1803 456.1 1804 456.1 1805 456.1 1806 456.1 1807 456.1 1808 456.1 1809 456.1 1810 456.1 1811 456.1 1812 456.1 1813 456.1 1814 456.1 1815 456.1 1816 456.1 1817 456.1 1818 456.1 1819 456.1 1820 442.5 1821 429.2 1822 417.4 1823 404.7 1824 392.2 1825 392.2 1826 392.2 1827 392.2 1828 392.2 1829 392.2 1830 392.2 1831 392.2 1832 392.2 1833 392.2 1834 392.2 1835 392.2 1836 392.2 1837 392.2 1838 392.2 1839 392.2 1840 392.2 1841 392.2 1842 392.2 1843 392.2 1844 392.2 1845 392.2 1846 392.2 1847 392.2 1848 392.2 1849 392.2 1850 392.2 1851 392.2 1852 392.2 1853 392.2 1854 392.2 1855 392.2 1856 392.2 1857 392.2 1858 392.2 1859 392.2 1860 392.2 1861 392.2 1862 392.2 1863 392.2 1864 392.2 1865 392.2 1866 392.2 1867 392.2 1868 392.2 1869 392.2 1870 392.2 1871 392.2 1872 392.2 1873 392.2 1874 392.2 1875 392.2 1876 392.2 1877 392.2 1878 392.2 1879 392.2 1880 392.2 1881 392.2 1882 392.2 1883 392.2 1884 392.2 1885 392.2 1886 392.2 1887 392.2 1888 392.2 1889 392.2 1890 392.2 1891 392.2 1892 392.2 1893 392.2 1894 392.2 1895 392.2 1896 392.1 1897 392 1898 391.9 1899 391.6 1900 391.4 1901 391 1902 390.6 1903 390.2 1904 389.6 1905 389.1 1906 388.4 1907 387.7 1908 386.9 1909 386.1 1910 385.3 1911 384.4 1912 383.5 1913 382.6 1914 381.6 1915 380.7 1916 379.8 1917 378.9 1918 377.9 1919 377 1920 376.1 1930 348 1931 322 1932 287.7 1933 273.2 1934 274.7 1935 258.5 1936 279.4 1937 251.5 1938 258.5 1939 207.2 1940 229.6 1943 315.5 1944 462.8 1945 351.2 1946 131.2 1947 125.9 1948 115.4 1949 100.2 1950 117.2 1951 105.2 1952 96.88 1953 84.8 1954 78.1 1955 72 1956 66.5 1957 61.5 1958 56.9 1959 52.3 1960 47.8 1961 43.7 1962 40.5 1963 38.2 1964 36.5 1965 35 1966 33.6 1967 32 1968 30.3 1969 28.7 1970 27.4 1971 26.1 1972 24.3 1973 22 1974 19.7 1975 17.6 1976 16.1 1977 15.2 1978 15.1 1979 15.2 1980 14.8 1981 14.1 1982 13.2 1983 12.3 1984 11.6 1985 10.9 1986 10.4 1987 9.8 1988 9.2 1989 8.4 1990 7.7 1991 6.9 1992 6.3 1993 5.8 1994 5.4 1995 5.2 1996 5 1997 4.8 1998 4.5 1999 4.3 2000 4 2001 3.7 2002 3.4 2003 3.2 2004 3 2005 2.9 2006 2.9 2007 2.9 2008 2.8 2009 2.8 2010 2.8 2011 2.8 2012 2.8 2013 2.8