Year Total
1800 5.2
1801 5.19
1802 5.18
1803 5.18
1804 5.17
1805 5.16
1806 5.15
1807 5.14
1808 5.14
1809 5.13
1810 5.12
1811 5.11
1812 5.1
1813 5.1
1814 5.09
1815 5.08
1816 5.07
1817 5.06
1818 5.06
1819 5.05
1820 5.04
1821 5.03
1822 5.02
1823 5.02
1824 5.01
1825 5
1826 4.99
1827 4.98
1828 4.98
1829 4.97
1830 4.96
1831 4.95
1832 4.94
1833 4.94
1834 4.93
1835 4.92
1836 4.91
1837 4.9
1838 4.9
1839 4.89
1840 4.88
1841 4.87
1842 4.86
1843 4.86
1844 4.85
1845 4.84
1846 4.83
1847 4.82
1848 4.82
1849 4.81
1850 4.8
1851 4.77
1852 4.75
1853 4.72
1854 4.69
1855 4.67
1856 4.64
1857 4.61
1858 4.59
1859 4.56
1860 4.54
1861 4.51
1862 4.48
1863 4.46
1864 4.43
1865 4.4
1866 4.38
1867 4.35
1868 4.32
1869 4.3
1870 4.27
1871 4.24
1872 4.22
1873 4.19
1874 4.17
1875 4.14
1876 4.11
1877 4.09
1878 4.06
1879 4.03
1880 4.01
1881 3.98
1882 3.95
1883 3.93
1884 3.9
1885 3.87
1886 3.85
1887 3.82
1888 3.8
1889 3.77
1890 3.74
1891 3.72
1892 3.69
1893 3.66
1894 3.64
1895 3.61
1896 3.58
1897 3.56
1898 3.54
1899 3.52
1900 3.5
1901 3.47
1902 3.45
1903 3.43
1904 3.41
1905 3.39
1906 3.37
1907 3.35
1908 3.33
1909 3.31
1910 3.29
1911 3.27
1912 3.25
1913 3.22
1914 3.2
1915 3.18
1916 3.16
1917 3.14
1918 3.12
1919 3.1
1920 3.08
1921 3.06
1922 3.04
1923 3.02
1924 3
1925 2.97
1926 2.91
1927 2.85
1928 2.78
1929 2.72
1930 2.65
1931 2.59
1932 2.54
1933 2.48
1934 2.42
1935 2.36
1936 2.38
1937 2.41
1938 2.44
1939 2.46
1940 2.49
1941 2.44
1942 2.39
1943 2.35
1944 2.3
1945 2.25
1946 2.2
1947 2.15
1948 2.11
1949 2.06
1950 2.01
1951 2.01
1952 2
1953 2
1954 1.99
1955 1.98
1956 1.97
1957 1.96
1958 1.94
1959 1.93
1960 1.91
1961 1.9
1962 1.88
1963 1.86
1964 1.85
1965 1.84
1966 1.84
1967 1.85
1968 1.87
1969 1.9
1970 1.93
1971 1.95
1972 1.96
1973 1.97
1974 1.96
1975 1.95
1976 1.93
1977 1.92
1978 1.91
1979 1.92
1980 1.94
1981 1.98
1982 2.02
1983 2.07
1984 2.11
1985 2.15
1986 2.16
1987 2.14
1988 2.1
1989 2.03
1990 1.94
1991 1.83
1992 1.7
1993 1.58
1994 1.46
1995 1.36
1996 1.27
1997 1.22
1998 1.18
1999 1.17
2000 1.18
2001 1.21
2002 1.25
2003 1.3
2004 1.35
2005 1.4
2006 1.43
2007 1.46
2008 1.49
2009 1.5
2010 1.51
2011 1.51
2012 1.51
2013 1.51
2014 1.52
2015 1.53
2016 1.54
2017 1.56
2018 1.57