Year Total 1800 5.81 1801 5.81 1802 5.81 1803 5.81 1804 5.81 1805 5.81 1806 5.81 1807 5.81 1808 5.81 1809 5.81 1810 5.81 1811 5.81 1812 5.81 1813 5.81 1814 5.81 1815 5.81 1816 5.81 1817 5.81 1818 5.81 1819 5.81 1820 5.81 1821 5.81 1822 5.81 1823 5.81 1824 5.81 1825 5.81 1826 5.81 1827 5.81 1828 5.81 1829 5.81 1830 5.81 1831 5.81 1832 5.81 1833 5.81 1834 5.81 1835 5.81 1836 5.81 1837 5.81 1838 5.81 1839 5.81 1840 5.81 1841 5.81 1842 5.81 1843 5.81 1844 5.81 1845 5.81 1846 5.81 1847 5.81 1848 5.81 1849 5.81 1850 5.81 1851 5.81 1852 5.81 1853 5.81 1854 5.81 1855 5.81 1856 5.81 1857 5.81 1858 5.81 1859 5.81 1860 5.81 1861 5.81 1862 5.81 1863 5.81 1864 5.81 1865 5.81 1866 5.81 1867 5.81 1868 5.81 1869 5.81 1870 5.81 1871 5.81 1872 5.81 1873 5.81 1874 5.81 1875 5.81 1876 5.81 1877 5.81 1878 5.81 1879 5.81 1880 5.81 1881 5.81 1882 5.81 1883 5.81 1884 5.81 1885 5.81 1886 5.81 1887 5.81 1888 5.81 1889 5.81 1890 5.81 1891 5.81 1892 5.81 1893 5.81 1894 5.81 1895 5.81 1896 5.81 1897 5.81 1898 5.81 1899 5.81 1900 5.81 1901 5.81 1902 5.81 1903 5.81 1904 5.81 1905 5.81 1906 5.81 1907 5.81 1908 5.81 1909 5.81 1910 5.81 1911 5.81 1912 5.81 1913 5.81 1914 5.81 1915 5.81 1916 5.81 1917 5.81 1918 5.81 1919 5.81 1920 5.81 1921 5.81 1922 5.81 1923 5.81 1924 5.81 1925 5.81 1926 5.78 1927 5.76 1928 5.73 1929 5.71 1930 5.68 1931 5.66 1932 5.63 1933 5.61 1934 5.58 1935 5.56 1936 5.53 1937 5.51 1938 5.48 1939 5.46 1940 5.43 1941 5.41 1942 5.38 1943 5.36 1944 5.33 1945 5.31 1946 5.28 1947 5.26 1948 5.23 1949 5.21 1950 5.18 1951 5.36 1952 5.69 1953 5.97 1954 6.22 1955 6.43 1956 6.59 1957 6.71 1958 6.78 1959 6.79 1960 6.74 1961 6.63 1962 6.44 1963 6.2 1964 5.91 1965 5.6 1966 5.3 1967 5.04 1968 4.84 1969 4.69 1970 4.6 1971 4.56 1972 4.54 1973 4.51 1974 4.48 1975 4.44 1976 4.39 1977 4.34 1978 4.3 1979 4.27 1980 4.25 1981 4.24 1982 4.24 1983 4.25 1984 4.24 1985 4.23 1986 4.2 1987 4.15 1988 4.07 1989 3.97 1990 3.84 1991 3.7 1992 3.55 1993 3.4 1994 3.25 1995 3.12 1996 2.99 1997 2.87 1998 2.76 1999 2.67 2000 2.58 2001 2.51 2002 2.46 2003 2.41 2004 2.37 2005 2.34 2006 2.32 2007 2.3 2008 2.28 2009 2.26 2010 2.24 2011 2.22 2012 2.19 2013 2.17 2014 2.15 2015 2.13 2016 2.1 2017 2.08 2018 2.06