Year Years
1800 32
1801 32
1802 32
1803 32
1804 32
1805 32
1806 32
1807 32
1808 32
1809 32
1810 32
1811 32
1812 32
1813 32
1814 32
1815 32
1816 32
1817 32
1818 32
1819 32
1820 32
1821 32
1822 32
1823 32
1824 32
1825 32
1826 32
1827 32
1828 32
1829 32
1830 32
1831 32
1832 32
1833 32
1834 32
1835 32
1836 32
1837 32
1838 32
1839 32
1840 32
1841 32
1842 32
1843 32
1844 32
1845 32
1846 32
1847 32
1848 32
1849 32
1850 32
1851 32
1852 32
1853 32
1854 32
1855 32
1856 32
1857 32
1858 32
1859 32
1860 32
1861 32
1862 32
1863 32
1864 32
1865 32
1866 32
1867 32
1868 32
1869 32
1870 32
1871 31.97
1872 31.94
1873 31.91
1874 31.88
1875 31.85
1876 31.81
1877 31.78
1878 31.75
1879 31.72
1880 31.69
1881 31.66
1882 31.63
1883 31.6
1884 31.57
1885 31.54
1886 31.51
1887 31.48
1888 31.44
1889 31.41
1890 31.38
1891 31.35
1892 31.32
1893 31.29
1894 31.26
1895 31.23
1896 31.2
1897 31.17
1898 31.14
1899 31.11
1900 31.07
1901 31.04
1902 31.01
1903 30.98
1904 30.95
1905 30.92
1906 30.89
1907 30.86
1908 30.83
1909 30.8
1910 30.77
1911 30.74
1912 30.7
1913 30.67
1914 30.64
1915 30.61
1916 30.58
1917 30.55
1918 19.56
1919 30.49
1920 30.46
1921 30.43
1922 30.4
1923 30.37
1924 30.33
1925 30.3
1926 30.27
1927 30.24
1928 30.21
1929 30.18
1930 30.15
1931 30.28
1932 30.4
1933 30.53
1934 30.65
1935 30.77
1936 30.9
1937 32.13
1938 33.35
1939 34.58
1940 33.57
1941 32.7
1942 32.11
1943 30.68
1944 25.07
1945 15.77
1946 33.36
1947 38.88
1948 43.47
1949 46.19
1950 47.85
1951 48.2
1952 48.93
1953 49.63
1954 50.31
1955 50.96
1956 51.6
1957 52.2
1958 52.79
1959 53.36
1960 53.94
1961 54.5
1962 55.05
1963 55.57
1964 56.02
1965 56.31
1966 56.32
1967 56.01
1968 55.43
1969 54.65
1970 53.85
1971 54.53
1972 50.59
1973 54.62
1974 53.61
1975 61.19
1976 63.03
1977 63.42
1978 63.82
1979 63.14
1980 64.46
1981 64.92
1982 65.31
1983 65.7
1984 66.15
1985 66.53
1986 66.92
1987 67.25
1988 67.62
1989 67.9
1990 68.19
1991 68.43
1992 68.7
1993 68.95
1994 69.21
1995 69.49
1996 69.75
1997 69.93
1998 70.28
1999 70.49
2000 70.71
2001 70.93
2002 71.14
2003 71.34
2004 71.54
2005 71.77
2006 72.01
2007 72.28
2008 72.53
2009 72.79
2010 73.07
2011 73.34
2012 73.6
2013 73.83
2014 74.06
2015 74.28
2016 74.49
2017 74.68
2018 74.88