Year Years
1800 33.1
1801 33.1
1802 33.1
1803 33.1
1804 33.1
1805 33.1
1806 33.1
1807 33.1
1808 33.1
1809 33.1
1810 33.1
1811 33.1
1812 33.1
1813 33.1
1814 33.1
1815 33.1
1816 33.1
1817 33.1
1818 33.1
1819 33.1
1820 33.1
1821 33.1
1822 33.1
1823 33.1
1824 33.1
1825 33.1
1826 33.1
1827 33.1
1828 33.1
1829 33.1
1830 33.1
1831 33.1
1832 33.1
1833 33.1
1834 33.1
1835 33.1
1836 33.1
1837 33.1
1838 33.1
1839 33.1
1840 33.1
1841 33.1
1842 33.1
1843 33.1
1844 33.1
1845 33.1
1846 33.1
1847 33.1
1848 33.1
1849 33.1
1850 33.1
1851 33.1
1852 33.1
1853 33.1
1854 33.1
1855 33.1
1856 33.1
1857 33.1
1858 33.1
1859 33.1
1860 33.1
1861 33.1
1862 33.1
1863 33.1
1864 33.1
1865 33.1
1866 33.1
1867 33.1
1868 33.1
1869 33.1
1870 33.1
1871 33.12
1872 33.13
1873 33.15
1874 33.17
1875 33.19
1876 33.2
1877 33.22
1878 33.24
1879 33.25
1880 33.27
1881 33.29
1882 33.31
1883 33.32
1884 33.34
1885 33.36
1886 33.37
1887 33.39
1888 33.41
1889 33.43
1890 33.44
1891 33.46
1892 33.48
1893 33.49
1894 33.51
1895 33.53
1896 33.55
1897 33.56
1898 33.58
1899 33.6
1900 33.61
1901 33.63
1902 33.65
1903 33.67
1904 33.68
1905 33.7
1906 33.72
1907 33.73
1908 33.75
1909 33.77
1910 33.79
1911 33.8
1912 33.82
1913 33.84
1914 33.85
1915 33.87
1916 33.89
1917 33.91
1918 25.96
1919 33.94
1920 33.96
1921 33.97
1922 33.99
1923 34.01
1924 34.03
1925 34.04
1926 34.06
1927 34.08
1928 34.09
1929 34.11
1930 34.13
1931 34.15
1932 34.16
1933 34.18
1934 34.2
1935 34.22
1936 34.23
1937 34.25
1938 34.27
1939 34.28
1940 34.3
1941 35.55
1942 36.81
1943 38.07
1944 39.32
1945 40.59
1946 41.85
1947 43.11
1948 44.37
1949 45.63
1950 46.91
1951 47.09
1952 47.43
1953 47.79
1954 48.17
1955 48.56
1956 48.96
1957 49.38
1958 49.81
1959 50.27
1960 50.72
1961 51.19
1962 51.66
1963 52.14
1964 52.61
1965 53.08
1966 53.55
1967 53.99
1968 54.44
1969 54.88
1970 55.31
1971 55.8
1972 56.34
1973 56.84
1974 57.41
1975 57.81
1976 58.48
1977 59.14
1978 59.74
1979 60.32
1980 61
1981 61.66
1982 62.66
1983 63.28
1984 63.98
1985 64.62
1986 65.17
1987 65.65
1988 66.12
1989 66.61
1990 67.2
1991 67.6
1992 67.93
1993 68.2
1994 68.65
1995 68.99
1996 69.49
1997 69.8
1998 70.21
1999 70.51
2000 70.87
2001 71.19
2002 71.45
2003 71.71
2004 71.93
2005 72.22
2006 72.48
2007 72.74
2008 73.01
2009 73.29
2010 73.55
2011 73.81
2012 74.08
2013 74.34
2014 74.56
2015 74.78
2016 74.99
2017 75.23
2018 75.46