# year    value 
 1900 9.739747 
 1901 9.736547 
 1902  9.67367 
 1903 9.226271 
 1904 9.403399 
 1905 9.585358 
 1906 9.578282 
 1907 9.585988 
 1908 9.627875 
 1909 9.651786 
 1910 9.644988 
 1911 9.674096 
 1912 9.577015 
 1913  9.44977 
 1914 9.625542 
 1915 9.748006 
 1916  9.82667 
 1917 9.815175 
 1918   9.8319 
 1919  9.78434 
 1920 9.812661 
 1921 9.815135 
 1922 9.900993 
 1923 9.818172 
 1924 9.843014 
 1925 9.880782 
 1926  9.87996 
 1927 9.881436 
 1928 9.872738 
 1929 9.828298 
 1930 9.838925 
 1931 9.806624 
 1932 9.836369 
 1933 9.767697 
 1934 9.842813 
 1935 9.842979 
 1936 9.901513 
 1937 9.850133 
 1938 9.923417 
 1939 9.846536 
 1940 9.936253 
 1941 9.826703 
 1942 9.921099 
 1943 9.848557 
 1944 9.841318 
 1945 9.915951 
 1946 9.878306 
 1947 9.933104 
 1948 9.897839 
 1949 10.01019 
 1950 9.979349 
 1951 9.898798 
 1952 9.904439 
 1953 9.903616 
 1954 9.923931 
 1955 9.905834 
 1956  9.83656 
 1957 9.843683 
 1958 9.879291 
 1959 9.882938 
 1960 9.914544 
 1961 9.820858 
 1962 9.786436 
 1963 9.740872 
 1964 9.587399 
 1965 9.590647 
 1966 9.695803 
 1967 9.702539 
 1968 9.658614 
 1969 9.643913 
 1970 9.799506 
 1971 9.859879 
 1972 9.849155 
 1973 9.887473 
 1974  9.94115 
 1975 9.844299 
 1976 9.877525 
 1977 9.988047 
 1978 9.988081 
 1979 10.02967 
 1980 10.11974 
 1981  10.1516 
 1982 9.933908 
 1983 9.731507 
 1984  9.91312 
 1985 9.991242 
 1986 9.987655 
 1987  10.0603 
 1988 10.16609 
 1989 10.24004 
 1990 10.25633 
 1991 10.23308 
 1992 9.751943 
 1993 9.954914 
 1994 10.10076 
 1995 10.20625 
 1996 10.27524 
 1997 10.38287 
 1998 10.46451 
 1999 10.44228 
 2000 10.51831 
 2001 10.60661 
 2002 10.58668 
 2003 10.58944 
 2004 10.62324 
 2005 10.68761