Year Total 1800 5.71 1801 5.71 1802 5.71 1803 5.71 1804 5.71 1805 5.71 1806 5.71 1807 5.71 1808 5.71 1809 5.71 1810 5.71 1811 5.71 1812 5.71 1813 5.71 1814 5.71 1815 5.71 1816 5.71 1817 5.71 1818 5.71 1819 5.71 1820 5.71 1821 5.71 1822 5.71 1823 5.71 1824 5.71 1825 5.71 1826 5.71 1827 5.71 1828 5.71 1829 5.71 1830 5.71 1831 5.71 1832 5.71 1833 5.71 1834 5.71 1835 5.71 1836 5.71 1837 5.71 1838 5.71 1839 5.71 1840 5.71 1841 5.71 1842 5.71 1843 5.71 1844 5.71 1845 5.71 1846 5.71 1847 5.71 1848 5.71 1849 5.71 1850 5.71 1851 5.71 1852 5.71 1853 5.71 1854 5.71 1855 5.71 1856 5.71 1857 5.71 1858 5.71 1859 5.71 1860 5.71 1861 5.71 1862 5.71 1863 5.71 1864 5.71 1865 5.71 1866 5.71 1867 5.71 1868 5.71 1869 5.71 1870 5.71 1871 5.71 1872 5.71 1873 5.71 1874 5.71 1875 5.71 1876 5.71 1877 5.71 1878 5.71 1879 5.71 1880 5.71 1881 5.71 1882 5.71 1883 5.71 1884 5.71 1885 5.71 1886 5.71 1887 5.71 1888 5.71 1889 5.71 1890 5.71 1891 5.71 1892 5.71 1893 5.71 1894 5.71 1895 5.71 1896 5.71 1897 5.71 1898 5.71 1899 5.71 1900 5.71 1901 5.71 1902 5.71 1903 5.71 1904 5.71 1905 5.71 1906 5.71 1907 5.71 1908 5.71 1909 5.71 1910 5.71 1911 5.71 1912 5.71 1913 5.71 1914 5.71 1915 5.71 1916 5.71 1917 5.71 1918 5.71 1919 5.71 1920 5.71 1921 5.71 1922 5.71 1923 5.71 1924 5.71 1925 5.71 1926 5.71 1927 5.7 1928 5.7 1929 5.7 1930 5.7 1931 5.69 1932 5.69 1933 5.69 1934 5.69 1935 5.68 1936 5.68 1937 5.68 1938 5.68 1939 5.67 1940 5.67 1941 5.67 1942 5.66 1943 5.66 1944 5.66 1945 5.66 1946 5.65 1947 5.65 1948 5.65 1949 5.65 1950 5.64 1951 5.67 1952 5.71 1953 5.73 1954 5.75 1955 5.75 1956 5.75 1957 5.73 1958 5.7 1959 5.66 1960 5.62 1961 5.56 1962 5.5 1963 5.44 1964 5.36 1965 5.28 1966 5.18 1967 5.07 1968 4.94 1969 4.79 1970 4.61 1971 4.4 1972 4.17 1973 3.9 1974 3.62 1975 3.33 1976 3.06 1977 2.81 1978 2.59 1979 2.42 1980 2.29 1981 2.2 1982 2.15 1983 2.12 1984 2.11 1985 2.11 1986 2.11 1987 2.11 1988 2.1 1989 2.08 1990 2.05 1991 2.02 1992 1.99 1993 1.96 1994 1.93 1995 1.92 1996 1.9 1997 1.9 1998 1.89 1999 1.89 2000 1.9 2001 1.91 2002 1.93 2003 1.95 2004 1.97 2005 2 2006 2.02 2007 2.04 2008 2.04 2009 2.04 2010 2.02 2011 2 2012 1.98 2013 1.95 2014 1.93 2015 1.91 2016 1.9 2017 1.89 2018 1.88