Year Total
1800 4.07
1801 4.26
1802 4.5
1803 4.45
1804 4.52
1805 4.5
1806 4.36
1807 4.42
1808 4.31
1809 3.78
1810 4.67
1811 5.01
1812 4.76
1813 4.22
1814 4.42
1815 4.93
1816 5.01
1817 4.74
1818 4.8
1819 4.68
1820 4.68
1821 5.03
1822 5.09
1823 5.22
1824 4.9
1825 5.18
1826 4.94
1827 4.44
1828 4.77
1829 4.94
1830 4.67
1831 4.32
1832 4.38
1833 4.84
1834 4.78
1835 4.63
1836 4.52
1837 4.37
1838 4.17
1839 4.18
1840 4.46
1841 4.3
1842 4.49
1843 4.36
1844 4.56
1845 4.46
1846 4.25
1847 4.2
1848 4.3
1849 4.66
1850 4.45
1851 4.36
1852 4.2
1853 4.26
1854 4.53
1855 4.3
1856 4.23
1857 4.36
1858 4.66
1859 4.71
1860 4.71
1861 4.44
1862 4.59
1863 4.65
1864 4.69
1865 4.58
1866 4.68
1867 4.4
1868 3.93
1869 4.03
1870 4.11
1871 4.37
1872 4.34
1873 4.49
1874 4.54
1875 4.6
1876 4.57
1877 4.62
1878 4.44
1879 4.56
1880 4.36
1881 4.29
1882 4.32
1883 4.24
1884 4.4
1885 4.34
1886 4.39
1887 4.36
1888 4.24
1889 4.1
1890 4.15
1891 4.14
1892 3.93
1893 3.98
1894 3.94
1895 4.01
1896 3.98
1897 3.92
1898 3.99
1899 3.9
1900 4
1901 4
1902 3.91
1903 3.78
1904 3.77
1905 3.74
1906 3.73
1907 3.7
1908 3.7
1909 3.69
1910 3.55
1911 3.45
1912 3.39
1913 3.27
1914 3.2
1915 3.01
1916 2.93
1917 2.88
1918 2.78
1919 2.69
1920 3.19
1921 2.9
1922 2.63
1923 2.52
1924 2.4
1925 2.3
1926 2.18
1927 2.07
1928 2.05
1929 1.92
1930 1.93
1931 1.85
1932 1.8
1933 1.69
1934 1.68
1935 1.68
1936 1.73
1937 1.74
1938 1.8
1939 1.86
1940 1.82
1941 1.89
1942 2.16
1943 2.38
1944 2.56
1945 2.59
1946 2.55
1947 2.49
1948 2.46
1949 2.37
1950 2.28
1951 2.21
1952 2.24
1953 2.27
1954 2.2
1955 2.27
1956 2.31
1957 2.3
1958 2.28
1959 2.26
1960 2.2
1961 2.23
1962 2.26
1963 2.33
1964 2.48
1965 2.41
1966 2.36
1967 2.27
1968 2.07
1969 1.92
1970 1.92
1971 1.96
1972 1.91
1973 1.87
1974 1.88
1975 1.77
1976 1.68
1977 1.65
1978 1.6
1979 1.66
1980 1.68
1981 1.64
1982 1.63
1983 1.61
1984 1.66
1985 1.74
1986 1.8
1987 1.84
1988 1.97
1989 2.02
1990 2.14
1991 2.11
1992 2.08
1993 1.98
1994 1.88
1995 1.73
1996 1.6
1997 1.53
1998 1.52
1999 1.51
2000 1.56
2001 1.58
2002 1.67
2003 1.73
2004 1.77
2005 1.79
2006 1.87
2007 1.89
2008 1.92
2009 1.94
2010 1.99
2011 1.9
2012 1.91
2013 1.92
2014 1.92
2015 1.91
2016 1.91
2017 1.91
2018 1.91