Year Years
1800 391
1801 391
1802 391
1803 391
1804 391
1805 391
1806 391
1807 391
1808 391
1809 391
1810 391
1811 391
1812 391
1813 391
1814 391
1815 391
1816 391
1817 391
1818 391
1819 391
1820 391
1821 391
1822 391
1823 391
1824 391
1825 391
1826 391
1827 391
1828 391
1829 391
1830 391
1831 391
1832 391
1833 391
1834 391
1835 391
1836 391
1837 391
1838 391
1839 391
1840 391
1841 391
1842 391
1843 391
1844 391
1845 391
1846 391
1847 391
1848 391
1849 391
1850 391
1851 391
1852 391
1853 391
1854 391
1855 391
1856 391
1857 391
1858 391
1859 391
1860 391
1870 169.7
1871 156.7
1872 182.8
1873 175.3
1874 196
1875 222.2
1876 184.7
1877 199.7
1878 207.2
1879 177.2
1880 180.9
1881 179.1
1882 214.7
1883 188.4
1884 196
1885 201.6
1886 197.8
1887 179.1
1888 179.1
1889 209.1
1890 162.2
1891 177.2
1892 160.4
1893 179.1
1894 156.7
1895 151.1
1896 175.3
1897 158.5
1898 201.6
1899 179.1
1900 149.3
1901 156.7
1902 162.2
1903 169.7
1904 117.2
1905 117.2
1906 118.9
1907 115.4
1908 110.3
1909 100.2
1910 105.2
1911 93.6
1912 100.2
1913 100.2
1914 98.52
1915 93.6
1916 96.88
1917 75.01
1918 79.68
1919 95.24
1920 95.24
1921 89.08
1922 70.99
1923 79.48
1924 76.05
1925 69.76
1926 70.23
1927 72.27
1928 71.57
1929 68.14
1930 63.78
1931 54.35
1932 53.64
1933 53.3
1934 58.03
1935 53.59
1936 55.81
1937 50.67
1938 50.45
1939 50.47
1940 50.17
1941 52.49
1942 51.49
1943 50.27
1944 41.42
1945 37.93
1946 38.52
1947 35.78
1948 33.93
1949 31.51
1950 31.6
1951 31
1952 30.3
1953 29.5
1954 28.7
1955 28
1956 27.3
1957 26.6
1958 26
1959 25.4
1960 24.9
1961 24.3
1962 23.7
1963 23.2
1964 22.7
1965 22.4
1966 22.1
1967 22
1968 21.9
1969 21.7
1970 21.4
1971 20.9
1972 20.2
1973 19.4
1974 18.4
1975 17.3
1976 16.2
1977 15.3
1978 14.4
1979 13.6
1980 13
1981 12.5
1982 12.2
1983 11.8
1984 11.6
1985 11.3
1986 11
1987 10.6
1988 10.2
1989 9.7
1990 9.2
1991 8.6
1992 8.1
1993 7.7
1994 7.3
1995 7
1996 6.8
1997 6.6
1998 6.5
1999 6.4
2000 6.2
2001 6.1
2002 6
2003 5.9
2004 5.9
2005 5.7
2006 5.6
2007 5.4
2008 5.2
2009 5
2010 4.8
2011 4.5
2012 4.2
2013 4