Year Years
1800 32.2
1801 32.33
1802 32.45
1803 32.58
1804 32.7
1805 32.86
1806 33.02
1807 33.18
1808 33.34
1809 33.5
1810 33.64
1811 33.78
1812 33.92
1813 34.06
1814 34.2
1815 34.3
1816 34.4
1817 34.5
1818 34.6
1819 34.7
1820 35.04
1821 35.38
1822 35.72
1823 36.06
1824 36.4
1825 36.24
1826 36.08
1827 35.92
1828 35.76
1829 35.6
1830 35.74
1831 35.88
1832 36.02
1833 36.16
1834 36.3
1835 36.36
1836 36.42
1837 36.48
1838 36.54
1839 36.6
1840 36.48
1841 36.36
1842 36.24
1843 36.12
1844 36
1845 36.04
1846 36.08
1847 36.12
1848 36.16
1849 36.2
1850 36.26
1851 36.32
1852 36.38
1853 36.44
1854 36.5
1855 36.52
1856 36.54
1857 36.56
1858 36.58
1859 36.6
1860 36.24
1861 35.88
1862 35.52
1863 35.16
1864 34.8
1865 33.76
1866 32.72
1867 31.68
1868 30.64
1869 29.6
1870 29.66
1871 29.73
1872 29.8
1873 29.87
1874 29.94
1875 31.13
1876 32.32
1877 33.51
1878 34.71
1879 35.9
1880 36.96
1881 38.01
1882 39.07
1883 40.12
1884 41.18
1885 41.74
1886 42.29
1887 42.85
1888 43.4
1889 43.96
1890 39.79
1891 35.61
1892 31.44
1893 27.26
1894 23.07
1895 22.27
1896 21.47
1897 20.67
1898 19.87
1899 19.07
1900 33.42
1901 33.64
1902 33.87
1903 34.09
1904 34.31
1905 34.53
1906 34.76
1907 34.98
1908 35.2
1909 35.44
1910 35.66
1911 35.89
1912 36.12
1913 36.34
1914 36.58
1915 36.8
1916 37.04
1917 37.27
1918 24.18
1919 37.73
1920 37.97
1921 38.26
1922 38.55
1923 38.84
1924 39.13
1925 39.43
1926 40
1927 40.56
1928 41.13
1929 41.71
1930 42.28
1931 42.92
1932 43.56
1933 44.2
1934 44.84
1935 45.48
1936 46.08
1937 46.69
1938 47.3
1939 47.9
1940 48.51
1941 49.23
1942 49.96
1943 50.68
1944 51.41
1945 52.13
1946 53.64
1947 55.15
1948 56.66
1949 58.18
1950 59.69
1951 60.01
1952 60.63
1953 61.25
1954 61.87
1955 62.49
1956 63.12
1957 63.74
1958 64.37
1959 64.99
1960 65.63
1961 66.29
1962 66.95
1963 67.61
1964 68.28
1965 68.95
1966 69.6
1967 70.24
1968 70.86
1969 71.44
1970 72
1971 72.37
1972 72.75
1973 73.04
1974 73.26
1975 73.47
1976 73.63
1977 73.77
1978 73.88
1979 74.11
1980 74.17
1981 74.33
1982 74.44
1983 74.49
1984 74.53
1985 74.54
1986 74.6
1987 74.63
1988 74.67
1989 74.78
1990 74.84
1991 74.9
1992 74.95
1993 74.95
1994 75.03
1995 75.23
1996 75.48
1997 75.71
1998 76.01
1999 76.28
2000 76.58
2001 76.86
2002 77.11
2003 77.3
2004 77.45
2005 77.61
2006 77.81
2007 77.98
2008 78.13
2009 78.26
2010 78.39
2011 78.53
2012 78.62
2013 78.69
2014 78.78
2015 78.89
2016 78.98
2017 79.16
2018 79.34