Year Total 1800 5.74 1801 5.74 1802 5.74 1803 5.74 1804 5.74 1805 5.74 1806 5.74 1807 5.74 1808 5.74 1809 5.74 1810 5.74 1811 5.74 1812 5.74 1813 5.74 1814 5.74 1815 5.74 1816 5.74 1817 5.74 1818 5.74 1819 5.74 1820 5.74 1821 5.74 1822 5.74 1823 5.74 1824 5.74 1825 5.74 1826 5.74 1827 5.74 1828 5.74 1829 5.74 1830 5.74 1831 5.74 1832 5.74 1833 5.74 1834 5.74 1835 5.74 1836 5.74 1837 5.74 1838 5.74 1839 5.74 1840 5.74 1841 5.74 1842 5.74 1843 5.74 1844 5.74 1845 5.74 1846 5.74 1847 5.74 1848 5.74 1849 5.74 1850 5.74 1851 5.74 1852 5.74 1853 5.74 1854 5.74 1855 5.74 1856 5.74 1857 5.74 1858 5.74 1859 5.74 1860 5.74 1861 5.74 1862 5.74 1863 5.74 1864 5.74 1865 5.74 1866 5.74 1867 5.74 1868 5.74 1869 5.74 1870 5.74 1871 5.74 1872 5.74 1873 5.74 1874 5.74 1875 5.74 1876 5.74 1877 5.74 1878 5.74 1879 5.74 1880 5.74 1881 5.74 1882 5.74 1883 5.74 1884 5.74 1885 5.74 1886 5.74 1887 5.74 1888 5.74 1889 5.74 1890 5.74 1891 5.74 1892 5.74 1893 5.74 1894 5.74 1895 5.74 1896 5.74 1897 5.74 1898 5.74 1899 5.74 1900 5.74 1901 5.74 1902 5.74 1903 5.74 1904 5.74 1905 5.74 1906 5.74 1907 5.74 1908 5.74 1909 5.74 1910 5.74 1911 5.74 1912 5.74 1913 5.74 1914 5.74 1915 5.74 1916 5.74 1917 5.74 1918 5.74 1919 5.74 1920 5.74 1921 5.74 1922 5.74 1923 5.74 1924 5.74 1925 5.74 1926 5.74 1927 5.74 1928 5.74 1929 5.74 1930 5.74 1931 5.74 1932 5.75 1933 5.75 1934 5.75 1935 5.75 1936 5.75 1937 5.75 1938 5.75 1939 5.75 1940 5.75 1941 5.75 1942 5.75 1943 5.75 1944 5.76 1945 5.76 1946 5.76 1947 5.76 1948 5.76 1949 5.76 1950 5.76 1951 5.75 1952 5.74 1953 5.73 1954 5.73 1955 5.73 1956 5.73 1957 5.74 1958 5.74 1959 5.74 1960 5.74 1961 5.72 1962 5.69 1963 5.65 1964 5.58 1965 5.5 1966 5.4 1967 5.3 1968 5.18 1969 5.06 1970 4.95 1971 4.84 1972 4.73 1973 4.63 1974 4.53 1975 4.44 1976 4.36 1977 4.27 1978 4.18 1979 4.09 1980 4 1981 3.9 1982 3.8 1983 3.69 1984 3.59 1985 3.48 1986 3.38 1987 3.28 1988 3.18 1989 3.09 1990 3 1991 2.92 1992 2.84 1993 2.77 1994 2.69 1995 2.62 1996 2.54 1997 2.47 1998 2.39 1999 2.31 2000 2.23 2001 2.13 2002 2.04 2003 1.94 2004 1.84 2005 1.75 2006 1.68 2007 1.63 2008 1.6 2009 1.6 2010 1.61 2011 1.64 2012 1.67 2013 1.7 2014 1.71 2015 1.72 2016 1.72 2017 1.71 2018 1.71