# year    value 
 1900 7.882205 
 1901 8.040684 
 1902 7.877594 
 1903  7.34446 
 1904 7.470733 
 1905 7.933852 
 1906 7.894525 
 1907 7.931139 
 1908 7.691808 
 1909 7.824198 
 1910 7.695566 
 1911 7.776216 
 1912 7.464867 
 1913 7.814767 
 1914 7.673019 
 1915 7.904155 
 1916 7.921077 
 1917 7.896286 
 1918  7.96495 
 1919 8.261774 
 1920 7.923759 
 1921 7.881865 
 1922 7.879335 
 1923 8.031363 
 1924 7.878897 
 1925 8.023979 
 1926 7.943481 
 1927 8.086583 
 1928 7.995026 
 1929  7.89933 
 1930 7.897064 
 1931 8.088024 
 1932 7.831649 
 1933 8.119143 
 1934 8.071308 
 1935 8.079871 
 1936  7.99557 
 1937 8.114867 
 1938 8.099623 
 1939 7.866815 
 1940  8.23917 
 1941 8.181476 
 1942 7.924348 
 1943 8.053039 
 1944 8.038116 
 1945 7.958318 
 1946 8.082341 
 1947 7.834508 
 1948 7.997028 
 1949 8.185999 
 1950 8.321045 
 1951 8.058252 
 1952 8.077927 
 1953 8.002364 
 1954 8.091128 
 1955 7.972409 
 1956 7.946081 
 1957  7.92657 
 1958 8.116858 
 1959 8.005307 
 1960 8.025864 
 1961 7.902678 
 1962 7.901353 
 1963 7.733708 
 1964 7.654416 
 1965 7.741056 
 1966 7.827111 
 1967 7.857436 
 1968 7.775235 
 1969 7.583408 
 1970 7.738629 
 1971  7.62501 
 1972 7.885043 
 1973 7.878191 
 1974 8.018357 
 1975 7.770569 
 1976 7.701031 
 1977 8.039713 
 1978 8.114369 
 1979 8.109476 
 1980 8.148337 
 1981 8.319131 
 1982 8.141983 
 1983 7.770472 
 1984 8.137972 
 1985  8.11393 
 1986 8.305487 
 1987 8.284126 
 1988 8.369722 
 1989 8.489266 
 1990 8.316776 
 1991 8.145317 
 1992 7.995002 
 1993 8.072693 
 1994  8.45936 
 1995 8.503952 
 1996 8.722973 
 1997 8.705194 
 1998 8.848948 
 1999  8.68572 
 2000 8.997447 
 2001 9.213466 
 2002 8.813476 
 2003 9.102179 
 2004 9.003735 
 2005 9.063862