Year Years
1800 29.7
1801 29.7
1802 29.7
1803 29.7
1804 29.7
1805 29.7
1806 29.7
1807 29.7
1808 29.7
1809 29.7
1810 29.7
1811 29.7
1812 29.7
1813 29.7
1814 29.7
1815 29.7
1816 29.7
1817 29.7
1818 29.7
1819 29.7
1820 29.7
1821 29.7
1822 29.7
1823 29.7
1824 29.7
1825 29.7
1826 29.7
1827 29.7
1828 29.7
1829 29.7
1830 29.7
1831 29.7
1832 29.7
1833 29.7
1834 29.7
1835 29.7
1836 29.7
1837 29.7
1838 29.7
1839 29.7
1840 29.7
1841 29.7
1842 29.7
1843 29.7
1844 29.7
1845 29.7
1846 29.7
1847 29.7
1848 29.7
1849 29.7
1850 29.7
1851 29.7
1852 29.7
1853 29.7
1854 29.7
1855 29.7
1856 29.7
1857 29.7
1858 29.7
1859 29.7
1860 29.7
1861 29.7
1862 29.7
1863 29.7
1864 29.7
1865 29.7
1866 29.7
1867 29.7
1868 29.7
1869 29.7
1870 29.7
1871 29.7
1872 29.7
1873 29.71
1874 29.71
1875 29.71
1876 29.71
1877 29.72
1878 29.72
1879 29.72
1880 29.72
1881 29.73
1882 29.73
1883 29.73
1884 29.73
1885 29.74
1886 29.74
1887 29.74
1888 29.74
1889 29.75
1890 29.75
1891 29.75
1892 29.75
1893 29.76
1894 29.76
1895 29.76
1896 29.76
1897 29.76
1898 29.77
1899 29.77
1900 29.77
1901 29.77
1902 29.78
1903 29.78
1904 29.78
1905 29.78
1906 29.79
1907 29.79
1908 29.79
1909 29.79
1910 29.8
1911 29.8
1912 29.8
1913 29.8
1914 29.81
1915 29.81
1916 29.81
1917 29.81
1918 24.72
1919 29.82
1920 29.82
1921 29.82
1922 29.83
1923 29.83
1924 29.83
1925 29.83
1926 29.83
1927 29.84
1928 29.84
1929 29.84
1930 29.84
1931 29.85
1932 29.85
1933 29.85
1934 29.85
1935 29.86
1936 29.86
1937 29.86
1938 29.86
1939 29.87
1940 29.87
1941 32.88
1942 35.89
1943 38.9
1944 41.9
1945 44.91
1946 47.92
1947 50.94
1948 53.95
1949 56.96
1950 59.98
1951 60.2
1952 60.66
1953 61.1
1954 61.53
1955 61.93
1956 62.32
1957 62.7
1958 63.06
1959 63.4
1960 63.73
1961 64.05
1962 64.35
1963 64.64
1964 64.93
1965 65.21
1966 65.49
1967 65.77
1968 66.05
1969 66.33
1970 66.61
1971 66.76
1972 67.07
1973 67.34
1974 67.89
1975 59.65
1976 34.93
1977 52.7
1978 52.8
1979 52.9
1980 53.15
1981 53.35
1982 45.93
1983 63.67
1984 63.98
1985 64.35
1986 64.61
1987 54.54
1988 54.63
1989 69.7
1990 69.15
1991 71.7
1992 72.01
1993 72.33
1994 73.1
1995 73.53
1996 74.05
1997 74.71
1998 75.29
1999 76.01
2000 76.45
2001 76.98
2002 77.37
2003 77.7
2004 78.02
2005 78.28
2006 77.97
2007 78.66
2008 79.14
2009 79.48
2010 79.85
2011 79.03
2012 80.19
2013 79.96
2014 80.03
2015 80.08
2016 80.11
2017 80.28
2018 80.45