Year Years
1800 24
1801 24
1802 24
1803 24
1804 24
1805 24
1806 24
1807 24
1808 24
1809 24
1810 24
1811 24
1812 24
1813 24
1814 24
1815 24
1816 24
1817 24
1818 24
1819 24
1820 24
1821 24
1822 24
1823 24
1824 24
1825 24
1826 24
1827 24
1828 24
1829 24
1830 24
1831 24
1832 24
1833 24
1834 24
1835 24
1836 24
1837 24
1838 24
1839 24
1840 24
1841 24
1842 24
1843 24
1844 24
1845 24
1846 24
1847 24
1848 24
1849 24
1850 24
1851 24
1852 24
1853 24
1854 24
1855 24
1856 24
1857 24
1858 24
1859 24
1860 24
1861 24
1862 24
1863 24
1864 23.17
1865 22.33
1866 21.5
1867 20.67
1868 19.84
1869 19.88
1870 19.92
1871 19.96
1872 19.99
1873 20.03
1874 20.22
1875 20.41
1876 20.61
1877 20.8
1878 20.99
1879 21.18
1880 21.37
1881 21.55
1882 21.74
1883 21.93
1884 22.12
1885 22.31
1886 22.5
1887 22.69
1888 22.88
1889 23.06
1890 23.25
1891 23.44
1892 23.63
1893 23.82
1894 24
1895 24.19
1896 24.38
1897 24.56
1898 24.38
1899 24.21
1900 24.04
1901 24.27
1902 24.51
1903 24.74
1904 24.98
1905 25.21
1906 25.45
1907 25.68
1908 25.92
1909 26.15
1910 26.39
1911 29.27
1912 29.68
1913 27.54
1914 27.12
1915 26.72
1916 26.71
1917 23.76
1918 13.96
1919 19.3
1920 14.89
1921 18.11
1922 18.98
1923 27.67
1924 30.1
1925 29.2
1926 32.31
1927 31.64
1928 33.1
1929 31.88
1930 31.19
1931 25.55
1932 17.76
1933 13.86
1934 33.44
1935 34.93
1936 36.53
1937 35.56
1938 37.18
1939 39.49
1940 37.08
1941 26.64
1942 22.75
1943 21.78
1944 29.5
1945 36.74
1946 43.74
1947 35.99
1948 43.77
1949 46.45
1950 48.65
1951 48.83
1952 49.22
1953 49.61
1954 50
1955 50.39
1956 50.78
1957 51.16
1958 51.54
1959 51.92
1960 52.3
1961 52.69
1962 53.07
1963 53.46
1964 53.85
1965 54.23
1966 54.6
1967 54.95
1968 55.29
1969 55.6
1970 55.89
1971 56.51
1972 57.06
1973 57.63
1974 58.17
1975 58.68
1976 59.2
1977 59.71
1978 60.22
1979 60.71
1980 61.21
1981 61.68
1982 62.06
1983 62.28
1984 62.59
1985 62.93
1986 63.16
1987 63.37
1988 63.49
1989 63.6
1990 63.7
1991 63.67
1992 63.55
1993 63.39
1994 63.19
1995 63.12
1996 63.07
1997 63.04
1998 63.13
1999 63.32
2000 63.69
2001 64.02
2002 64.3
2003 64.6
2004 64.93
2005 65.35
2006 65.84
2007 66.35
2008 66.87
2009 67.43
2010 67.94
2011 68.39
2012 68.84
2013 69.19
2014 69.57
2015 69.9
2016 70.24
2017 70.36
2018 70.48