Year Years 1800 372.8 1801 372.8 1802 372.8 1803 372.8 1804 372.8 1805 372.8 1806 372.8 1807 372.8 1808 372.8 1809 372.8 1810 372.8 1811 372.8 1812 372.8 1813 372.8 1814 372.8 1815 372.8 1816 372.8 1817 372.8 1818 372.8 1819 372.8 1820 372.8 1821 372.8 1822 372.8 1823 372.8 1824 372.8 1825 372.8 1826 372.8 1827 372.8 1828 372.8 1829 372.8 1830 372.8 1831 372.8 1832 372.8 1833 372.8 1834 372.8 1835 372.8 1836 372.8 1837 372.8 1838 372.8 1839 372.8 1840 372.8 1841 372.8 1842 372.8 1843 372.8 1844 372.8 1845 372.8 1846 372.8 1847 372.8 1848 372.8 1849 372.8 1850 372.8 1851 372.8 1852 372.8 1853 372.8 1854 372.8 1855 372.8 1856 372.8 1857 372.8 1858 372.8 1859 372.8 1860 372.8 1861 372.8 1862 372.8 1863 372.8 1864 372.8 1865 372.8 1866 372.8 1867 372.8 1868 372.8 1869 372.8 1870 372.8 1871 372.8 1872 372.8 1873 372.8 1874 372.8 1875 372.8 1876 372.8 1877 372.8 1878 372.8 1879 372.8 1880 372.8 1881 372.8 1882 372.8 1883 372.8 1884 372.8 1885 372.8 1886 372.8 1887 372.8 1888 372.8 1889 372.8 1890 372.8 1891 372.8 1892 372.8 1893 372.8 1894 372.8 1895 372.8 1896 372.7 1897 372.6 1898 372.5 1899 372.3 1900 372 1910 212.8 1913 260.2 1914 238.8 1915 238.8 1916 249.7 1917 238.8 1918 339.9 1919 295.9 1920 266.8 1921 238.8 1922 231.5 1923 266.8 1924 231.5 1925 209.1 1926 231.5 1927 227.8 1929 244.3 1930 231.5 1931 225.9 1932 237 1933 240.7 1934 231.5 1935 240.7 1936 224.1 1937 244.3 1938 218.5 1939 186.6 1940 202.8 1941 245.9 1942 219 1943 212.5 1944 194.3 1945 179.9 1946 178.6 1947 157.6 1948 158.1 1949 171.2 1950 143.2 1951 138 1952 143.7 1953 136.4 1954 130.5 1955 127.2 1956 124.3 1957 121.8 1958 119.6 1959 117.4 1960 114.6 1961 110.3 1962 104.3 1963 97.6 1964 91 1965 85.3 1966 80.8 1967 77.7 1968 75.1 1969 72 1970 68.2 1971 63.4 1972 58 1973 52.6 1974 47.8 1975 43.5 1976 39.4 1977 35.6 1978 32.3 1979 29.7 1980 27.6 1981 25.8 1982 24.2 1983 22.8 1984 21.6 1985 20.4 1986 19.3 1987 18.2 1988 17 1989 15.9 1990 14.7 1991 13.6 1992 12.4 1993 11.4 1994 10.5 1995 9.8 1996 9.1 1997 8.6 1998 8.2 1999 7.7 2000 7.2 2001 6.7 2002 6.1 2003 5.6 2004 5.1 2005 4.7 2006 4.4 2007 4.2 2008 4.1 2009 4 2010 3.9 2011 3.8 2012 3.8 2013 3.8