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 31
1852 30
1853 29
1854 28
1855 27
1856 26
1857 26.71
1858 27.43
1859 28.14
1860 28.85
1861 29.56
1862 30.28
1863 30.99
1864 31.7
1865 31.74
1866 31.79
1867 31.83
1868 31.87
1869 31.91
1870 31.96
1871 31.99
1872 31.98
1873 31.98
1874 31.97
1875 31.96
1876 29.45
1877 27.45
1878 25.15
1879 28.43
1880 31.92
1881 31.91
1882 31.9
1883 31.89
1884 31.88
1885 31.88
1886 31.87
1887 31.86
1888 31.85
1889 31.84
1890 31.84
1891 31.83
1892 31.82
1893 31.81
1894 31.8
1895 31.79
1896 31.79
1897 31.78
1898 31.77
1899 31.76
1900 31.75
1901 31.74
1902 31.74
1903 31.73
1904 31.72
1905 31.71
1906 31.7
1907 31.7
1908 31.69
1909 31.68
1910 31.67
1911 31.66
1912 31.65
1913 31.65
1914 31.64
1915 31.63
1916 31.62
1917 31.61
1918 22.13
1919 31.6
1920 31.59
1921 31.58
1922 31.57
1923 31.56
1924 31.56
1925 31.55
1926 31.89
1927 25.27
1928 32.59
1929 29.4
1930 33.28
1931 33.66
1932 34.05
1933 34.43
1934 34.82
1935 35.2
1936 35.59
1937 33.41
1938 33.27
1939 33.5
1940 33.74
1941 33.38
1942 31.41
1943 28.46
1944 34.33
1945 36.29
1946 37.75
1947 38.82
1948 39.3
1949 39.77
1950 40.73
1951 41.69
1952 42.65
1953 43.61
1954 45.47
1955 46.97
1956 49.33
1957 49.42
1958 49.02
1959 37.52
1960 30.9
1961 33.3
1962 43.45
1963 50.66
1964 52.03
1965 54.29
1966 55.4
1967 56.92
1968 57.91
1969 59.42
1970 61.04
1971 61.64
1972 62.14
1973 62.63
1974 62.98
1975 63.26
1976 62.84
1977 63.64
1978 63.88
1979 64.04
1980 64.22
1981 64.34
1982 64.86
1983 65.33
1984 65.71
1985 66.08
1986 66.32
1987 66.64
1988 66.69
1989 66.74
1990 67.05
1991 67.3
1992 67.5
1993 67.74
1994 68.02
1995 68.36
1996 68.7
1997 69.01
1998 69.34
1999 69.7
2000 70.03
2001 70.32
2002 70.65
2003 71.34
2004 71.91
2005 72.4
2006 73.01
2007 73.51
2008 73.75
2009 74.28
2010 74.59
2011 75.06
2012 75.43
2013 75.72
2014 75.89
2015 76.26
2016 76.6
2017 76.76
2018 76.92