Year Total
1800 5.59
1801 5.5
1802 5.41
1803 5.32
1804 5.25
1805 5.18
1806 5.1
1807 5.03
1808 4.96
1809 4.97
1810 4.99
1811 5.01
1812 5.02
1813 5.04
1814 5.02
1815 5
1816 4.97
1817 4.95
1818 4.93
1819 4.97
1820 5.01
1821 5.05
1822 5.09
1823 5.13
1824 5.12
1825 5.11
1826 5.09
1827 5.08
1828 5.07
1829 5.03
1830 5
1831 4.96
1832 4.93
1833 4.89
1834 4.82
1835 4.75
1836 4.68
1837 4.61
1838 4.54
1839 4.51
1840 4.48
1841 4.45
1842 4.42
1843 4.4
1844 4.38
1845 4.37
1846 4.36
1847 4.34
1848 4.33
1849 4.39
1850 4.46
1851 4.52
1852 4.59
1853 4.65
1854 4.66
1855 4.68
1856 4.69
1857 4.7
1858 4.72
1859 4.82
1860 4.93
1861 5.03
1862 5.13
1863 5.24
1864 5.04
1865 4.85
1866 4.65
1867 4.46
1868 4.26
1869 4.31
1870 4.36
1871 4.41
1872 4.46
1873 4.52
1874 4.46
1875 4.4
1876 4.35
1877 4.29
1878 4.23
1879 4.2
1880 4.16
1881 4.13
1882 4.1
1883 4.06
1884 4.04
1885 4.01
1886 3.99
1887 3.96
1888 3.94
1889 3.9
1890 3.87
1891 3.84
1892 3.8
1893 3.77
1894 3.79
1895 3.82
1896 3.85
1897 3.88
1898 3.91
1899 3.89
1900 3.88
1901 3.86
1902 3.84
1903 3.82
1904 3.76
1905 3.7
1906 3.63
1907 3.57
1908 3.51
1909 3.47
1910 3.43
1911 3.38
1912 3.34
1913 3.3
1914 3.15
1915 3.01
1916 2.87
1917 2.73
1918 2.59
1919 2.58
1920 2.57
1921 2.56
1922 2.55
1923 2.54
1924 2.53
1925 2.52
1926 2.51
1927 2.47
1928 2.42
1929 2.38
1930 2.33
1931 2.29
1932 2.25
1933 2.21
1934 2.17
1935 2.13
1936 2.14
1937 2.14
1938 2.15
1939 2.15
1940 2.16
1941 2.15
1942 2.14
1943 2.14
1944 2.13
1945 2.12
1946 2.12
1947 2.11
1948 2.1
1949 2.1
1950 2.09
1951 2.08
1952 2.07
1953 2.05
1954 2.04
1955 2.02
1956 2.01
1957 1.99
1958 1.98
1959 1.96
1960 1.95
1961 1.95
1962 1.94
1963 1.95
1964 1.95
1965 1.97
1966 1.99
1967 2.01
1968 2.04
1969 2.07
1970 2.1
1971 2.12
1972 2.13
1973 2.13
1974 2.13
1975 2.11
1976 2.1
1977 2.08
1978 2.07
1979 2.06
1980 2.06
1981 2.08
1982 2.1
1983 2.13
1984 2.17
1985 2.19
1986 2.19
1987 2.17
1988 2.12
1989 2.04
1990 1.94
1991 1.83
1992 1.71
1993 1.6
1994 1.51
1995 1.43
1996 1.38
1997 1.34
1998 1.32
1999 1.31
2000 1.32
2001 1.34
2002 1.38
2003 1.43
2004 1.48
2005 1.54
2006 1.58
2007 1.62
2008 1.64
2009 1.65
2010 1.64
2011 1.63
2012 1.62
2013 1.61
2014 1.61
2015 1.62
2016 1.63
2017 1.65
2018 1.66