# year    value 
 1900 7.868154 
 1901 8.020806 
 1902 7.851976 
 1903 7.324034 
 1904 7.428299 
 1905 7.918921 
 1906 7.881861 
 1907  7.91646 
 1908 7.663336 
 1909 7.793972 
 1910 7.652424 
 1911 7.770324 
 1912 7.435813 
 1913 7.799645 
 1914 7.645736 
 1915 7.877585 
 1916 7.908735 
 1917 7.869646 
 1918 7.934272 
 1919   8.2556 
 1920 7.912586 
 1921 7.850839 
 1922 7.840212 
 1923 8.005853 
 1924 7.857737 
 1925 8.006148 
 1926 7.920883 
 1927 8.068187 
 1928 7.976816 
 1929  7.87795 
 1930 7.884468 
 1931 8.056642 
 1932  7.80862 
 1933 8.107027 
 1934  8.05114 
 1935 8.058268 
 1936 7.972987 
 1937 8.105318 
 1938 8.075588 
 1939 7.849134 
 1940 8.222775 
 1941 8.164742 
 1942 7.891961 
 1943  8.01276 
 1944 8.014051 
 1945 7.942631 
 1946 8.046864 
 1947 7.805243 
 1948 7.971982 
 1949 8.170135 
 1950 8.304846 
 1951 8.021034 
 1952 8.068354 
 1953 7.991143 
 1954  8.08922 
 1955 7.947455 
 1956 7.925108 
 1957 7.925869 
 1958 8.108209 
 1959 7.997128 
 1960  8.00626 
 1961 7.885283 
 1962 7.864205 
 1963 7.702229 
 1964 7.653769 
 1965 7.716588 
 1966 7.795668 
 1967 7.821402 
 1968  7.76076 
 1969 7.570004 
 1970 7.712306 
 1971 7.602857 
 1972 7.862608 
 1973 7.866852 
 1974 7.998963 
 1975 7.734752 
 1976  7.67024 
 1977 8.026182 
 1978 8.094321 
 1979 8.101922 
 1980 8.133201 
 1981  8.31304 
 1982 8.136588 
 1983 7.762158 
 1984 8.109755 
 1985 8.097078 
 1986 8.300692 
 1987 8.282027 
 1988 8.356126 
 1989 8.460625 
 1990  8.29568 
 1991 8.125352 
 1992 7.957702 
 1993 8.044902 
 1994 8.433574 
 1995 8.497079 
 1996 8.719681 
 1997 8.666333 
 1998 8.826614 
 1999 8.668906 
 2000 8.975468 
 2001 9.201047 
 2002 8.813787 
 2003 9.092018 
 2004 8.997698 
 2005 9.058847