Year Total 1800 6.78 1801 6.78 1802 6.78 1803 6.78 1804 6.78 1805 6.78 1806 6.78 1807 6.78 1808 6.78 1809 6.78 1810 6.78 1811 6.78 1812 6.78 1813 6.78 1814 6.78 1815 6.78 1816 6.78 1817 6.78 1818 6.78 1819 6.78 1820 6.78 1821 6.78 1822 6.78 1823 6.78 1824 6.78 1825 6.78 1826 6.78 1827 6.78 1828 6.78 1829 6.78 1830 6.78 1831 6.78 1832 6.78 1833 6.78 1834 6.78 1835 6.78 1836 6.78 1837 6.78 1838 6.78 1839 6.78 1840 6.78 1841 6.78 1842 6.78 1843 6.78 1844 6.78 1845 6.78 1846 6.78 1847 6.78 1848 6.78 1849 6.78 1850 6.78 1851 6.78 1852 6.78 1853 6.78 1854 6.78 1855 6.78 1856 6.78 1857 6.78 1858 6.78 1859 6.78 1860 6.78 1861 6.78 1862 6.78 1863 6.78 1864 6.78 1865 6.78 1866 6.78 1867 6.78 1868 6.78 1869 6.78 1870 6.78 1871 6.78 1872 6.78 1873 6.78 1874 6.78 1875 6.78 1876 6.78 1877 6.78 1878 6.78 1879 6.78 1880 6.78 1881 6.78 1882 6.78 1883 6.78 1884 6.78 1885 6.78 1886 6.78 1887 6.78 1888 6.78 1889 6.78 1890 6.78 1891 6.78 1892 6.78 1893 6.78 1894 6.78 1895 6.78 1896 6.78 1897 6.78 1898 6.78 1899 6.78 1900 6.78 1901 6.78 1902 6.78 1903 6.78 1904 6.78 1905 6.78 1906 6.78 1907 6.78 1908 6.78 1909 6.78 1910 6.78 1911 6.78 1912 6.78 1913 6.78 1914 6.78 1915 6.78 1916 6.78 1917 6.78 1918 6.78 1919 6.78 1920 6.78 1921 6.78 1922 6.78 1923 6.78 1924 6.78 1925 6.78 1926 6.78 1927 6.78 1928 6.78 1929 6.78 1930 6.78 1931 6.78 1932 6.78 1933 6.78 1934 6.78 1935 6.78 1936 6.78 1937 6.79 1938 6.79 1939 6.79 1940 6.79 1941 6.79 1942 6.79 1943 6.79 1944 6.8 1945 6.8 1946 6.8 1947 6.8 1948 6.8 1949 6.81 1950 6.81 1951 6.81 1952 6.82 1953 6.82 1954 6.83 1955 6.85 1956 6.86 1957 6.88 1958 6.9 1959 6.92 1960 6.94 1961 6.96 1962 6.99 1963 7.02 1964 7.06 1965 7.1 1966 7.14 1967 7.18 1968 7.22 1969 7.26 1970 7.3 1971 7.35 1972 7.39 1973 7.43 1974 7.48 1975 7.52 1976 7.56 1977 7.59 1978 7.62 1979 7.64 1980 7.64 1981 7.64 1982 7.62 1983 7.59 1984 7.54 1985 7.47 1986 7.39 1987 7.29 1988 7.18 1989 7.05 1990 6.92 1991 6.8 1992 6.68 1993 6.58 1994 6.5 1995 6.42 1996 6.36 1997 6.31 1998 6.26 1999 6.2 2000 6.15 2001 6.1 2002 6.05 2003 6 2004 5.96 2005 5.9 2006 5.83 2007 5.73 2008 5.61 2009 5.47 2010 5.31 2011 5.15 2012 4.99 2013 4.86 2014 4.74 2015 4.65 2016 4.57 2017 4.51 2018 4.44