Year Total 1800 6.59 1801 6.59 1802 6.59 1803 6.59 1804 6.59 1805 6.59 1806 6.59 1807 6.59 1808 6.59 1809 6.59 1810 6.59 1811 6.59 1812 6.59 1813 6.59 1814 6.59 1815 6.59 1816 6.59 1817 6.59 1818 6.59 1819 6.59 1820 6.59 1821 6.59 1822 6.59 1823 6.59 1824 6.59 1825 6.59 1826 6.59 1827 6.59 1828 6.59 1829 6.59 1830 6.59 1831 6.59 1832 6.59 1833 6.59 1834 6.59 1835 6.59 1836 6.59 1837 6.59 1838 6.59 1839 6.59 1840 6.59 1841 6.59 1842 6.59 1843 6.59 1844 6.59 1845 6.59 1846 6.59 1847 6.59 1848 6.59 1849 6.59 1850 6.59 1851 6.59 1852 6.59 1853 6.59 1854 6.59 1855 6.59 1856 6.59 1857 6.59 1858 6.59 1859 6.59 1860 6.59 1861 6.59 1862 6.59 1863 6.59 1864 6.59 1865 6.59 1866 6.59 1867 6.59 1868 6.59 1869 6.59 1870 6.59 1871 6.59 1872 6.59 1873 6.59 1874 6.59 1875 6.59 1876 6.59 1877 6.59 1878 6.59 1879 6.59 1880 6.59 1881 6.59 1882 6.59 1883 6.59 1884 6.59 1885 6.59 1886 6.59 1887 6.59 1888 6.59 1889 6.59 1890 6.59 1891 6.59 1892 6.59 1893 6.59 1894 6.59 1895 6.59 1896 6.59 1897 6.59 1898 6.59 1899 6.59 1900 6.59 1901 6.59 1902 6.59 1903 6.59 1904 6.59 1905 6.59 1906 6.59 1907 6.59 1908 6.59 1909 6.59 1910 6.59 1911 6.59 1912 6.59 1913 6.59 1914 6.59 1915 6.59 1916 6.59 1917 6.59 1918 6.59 1919 6.59 1920 6.59 1921 6.59 1922 6.59 1923 6.59 1924 6.59 1925 6.59 1926 6.59 1927 6.59 1928 6.59 1929 6.59 1930 6.59 1931 6.59 1932 6.59 1933 6.59 1934 6.59 1935 6.59 1936 6.59 1937 6.59 1938 6.6 1939 6.6 1940 6.6 1941 6.6 1942 6.6 1943 6.6 1944 6.6 1945 6.6 1946 6.6 1947 6.6 1948 6.6 1949 6.6 1950 6.6 1951 6.6 1952 6.6 1953 6.6 1954 6.6 1955 6.6 1956 6.6 1957 6.6 1958 6.6 1959 6.6 1960 6.6 1961 6.6 1962 6.6 1963 6.6 1964 6.6 1965 6.6 1966 6.6 1967 6.6 1968 6.6 1969 6.6 1970 6.6 1971 6.6 1972 6.61 1973 6.61 1974 6.61 1975 6.61 1976 6.61 1977 6.6 1978 6.58 1979 6.56 1980 6.54 1981 6.51 1982 6.48 1983 6.46 1984 6.44 1985 6.41 1986 6.37 1987 6.31 1988 6.23 1989 6.14 1990 6.02 1991 5.9 1992 5.76 1993 5.62 1994 5.48 1995 5.34 1996 5.2 1997 5.05 1998 4.89 1999 4.73 2000 4.58 2001 4.44 2002 4.31 2003 4.21 2004 4.13 2005 4.07 2006 4.02 2007 3.98 2008 3.94 2009 3.9 2010 3.86 2011 3.8 2012 3.74 2013 3.68 2014 3.62 2015 3.55 2016 3.48 2017 3.41 2018 3.35