Year Years
1800 38.65
1801 37.35
1802 38.62
1803 37.32
1804 41.44
1805 42.32
1806 43.22
1807 40.05
1808 40.35
1809 41.74
1810 38.35
1811 39.89
1812 41.83
1813 43.04
1814 40.24
1815 41.13
1816 39.94
1817 41.04
1818 39.85
1819 40.52
1820 41.31
1821 41.78
1822 41.35
1823 40.05
1824 39.19
1825 39.94
1826 39.83
1827 41.14
1828 42.03
1829 41.56
1830 43.02
1831 40.84
1832 40.16
1833 41.35
1834 40.78
1835 41.1
1836 41.43
1837 40.2
1838 40.3
1839 40.88
1840 39.93
1841 41.7
1842 41.35
1843 41.86
1844 41.55
1845 42.56
1846 39.96
1847 38.33
1848 39.5
1849 37.38
1850 42.8
1851 41.42
1852 40.93
1853 40.56
1854 39.34
1855 41.03
1856 43.25
1857 41.88
1858 40.04
1859 40.84
1860 43.01
1861 42.38
1862 42.52
1863 40.4
1864 39.97
1865 40.65
1866 40.41
1867 42.62
1868 42
1869 41.67
1870 40.95
1871 41.31
1872 42.9
1873 43.78
1874 42.13
1875 41.85
1876 43.68
1877 44.69
1878 43
1879 44.26
1880 43.77
1881 46.1
1882 44.86
1883 45.08
1884 44.78
1885 45.75
1886 45.31
1887 45.63
1888 46.79
1889 46.32
1890 44.73
1891 44.27
1892 45.49
1893 44.85
1894 48.31
1895 45.71
1896 47.38
1897 47.2
1898 46.95
1899 46.1
1900 46.29
1901 47.88
1902 49.05
1903 50.39
1904 49.07
1905 50.82
1906 50.54
1907 51.4
1908 51.8
1909 52.48
1910 53.94
1911 51.49
1912 54.5
1913 53.78
1914 51.94
1915 48.15
1916 47.68
1917 45.52
1918 40.39
1919 54.06
1920 56.54
1921 58.29
1922 57.07
1923 59.33
1924 58.1
1925 58.44
1926 59.59
1927 58.97
1928 59.91
1929 57.64
1930 60.81
1931 60.03
1932 60.55
1933 60.59
1934 61.31
1935 61.96
1936 61.76
1937 61.79
1938 63.21
1939 63.59
1940 60.88
1941 61.28
1942 63.89
1943 63.91
1944 64.75
1945 65.74
1946 66.36
1947 66.33
1948 68.38
1949 68.07
1950 68.58
1951 68.18
1952 69.48
1953 69.74
1954 70.11
1955 70.08
1956 70.35
1957 70.47
1958 70.64
1959 70.74
1960 70.96
1961 70.71
1962 70.78
1963 70.69
1964 71.47
1965 71.46
1966 71.38
1967 72.01
1968 71.64
1969 71.6
1970 71.84
1971 71.96
1972 72
1973 72.16
1974 72.31
1975 72.5
1976 72.7
1977 72.97
1978 73.11
1979 73.28
1980 73.54
1981 73.79
1982 73.97
1983 74.21
1984 74.45
1985 74.56
1986 74.75
1987 75
1988 75.19
1989 75.4
1990 75.66
1991 75.88
1992 76.11
1993 76.23
1994 76.48
1995 76.63
1996 76.85
1997 77.08
1998 77.27
1999 77.47
2000 77.78
2001 78.04
2002 78.25
2003 78.39
2004 78.76
2005 79.04
2006 79.33
2007 79.58
2008 79.83
2009 80.12
2010 80.34
2011 80.54
2012 80.65
2013 80.74
2014 80.8
2015 80.84
2016 80.89
2017 81.04
2018 81.19