Year Years 1800 329 1801 326.8 1802 324.6 1803 322.4 1804 321.3 1805 320.2 1806 318 1807 317 1808 315.9 1809 314.8 1810 313.7 1811 311.5 1812 310.4 1813 308.3 1814 309.4 1815 310.4 1816 311.5 1817 312.6 1818 313.7 1819 313.7 1820 314.8 1821 315.9 1822 317 1823 317 1824 314.8 1825 312.6 1826 311.5 1827 309.4 1828 307.2 1829 308.3 1830 309.4 1831 310.4 1841 251.1 1842 261.6 1843 258.3 1844 259 1845 248.3 1846 281.4 1847 281.6 1848 278.6 1849 279.9 1850 247.4 1851 262.3 1852 267.2 1853 264.4 1854 281.9 1855 261 1856 247.3 1857 262.5 1858 280.7 1859 273.9 1860 244.3 1861 258.5 1862 253.7 1863 279.5 1864 271.8 1865 266.9 1866 268.9 1867 248.3 1868 262.9 1869 262.9 1870 268.4 1871 258.1 1872 243.6 1873 235.4 1874 252.8 1875 252.2 1876 238.6 1877 225.1 1878 251.6 1879 228.2 1880 251.1 1881 209.8 1882 232.6 1883 221.5 1884 233.2 1885 218.9 1886 230.6 1887 227.1 1888 212.9 1889 227.8 1890 232 1891 232.9 1892 227.6 1893 236.2 1894 207.3 1895 236.9 1896 225.2 1897 226.3 1898 231.2 1899 232.3 1900 225.5 1901 215.6 1902 199.4 1903 191.2 1904 208.6 1905 185.9 1906 190.1 1907 176 1908 175.7 1909 162.9 1910 155.9 1911 189.2 1912 145.8 1913 157.9 1914 155.5 1915 165.8 1916 133.7 1917 136.6 1918 171.1 1919 134.8 1920 133.6 1921 114.1 1922 120.1 1923 102.3 1924 114.2 1925 112.5 1926 103.2 1927 103.6 1928 98.08 1929 113.8 1930 89.43 1931 95.38 1932 92.78 1933 87.72 1934 86.47 1935 80.54 1936 83.32 1937 80.48 1938 73.5 1939 65.9 1940 77.25 1941 81.31 1942 68.03 1943 64.65 1944 59.49 1945 55.1 1946 53.59 1947 53.54 1948 40.16 1949 38.27 1950 36.6 1951 35.1 1952 33.6 1953 32.1 1954 30.8 1955 29.6 1956 28.7 1957 27.9 1958 27.4 1959 27 1960 26.6 1961 26.1 1962 25.6 1963 24.9 1964 24.2 1965 23.4 1966 22.8 1967 22.2 1968 21.8 1969 21.4 1970 21 1971 20.6 1972 20.1 1973 19.4 1974 18.7 1975 18 1976 17.2 1977 16.5 1978 15.7 1979 14.9 1980 14.1 1981 13.4 1982 12.7 1983 12.2 1984 11.7 1985 11.4 1986 11.1 1987 10.8 1988 10.4 1989 9.9 1990 9.3 1991 8.7 1992 8.2 1993 7.8 1994 7.4 1995 7.2 1996 7 1997 6.9 1998 6.8 1999 6.7 2000 6.6 2001 6.5 2002 6.3 2003 6.3 2004 6.1 2005 6 2006 5.9 2007 5.8 2008 5.6 2009 5.4 2010 5.2 2011 5 2012 4.8 2013 4.6