# year    value 
 1900 4.605825 
 1901 4.563507 
 1902  4.53362 
 1903 4.202065 
 1904 4.305737 
 1905 4.444608 
 1906 4.490819 
 1907 4.474679 
 1908 4.510708 
 1909 4.535225 
 1910 4.553721 
 1911 4.545313 
 1912 4.510353 
 1913 4.409724 
 1914 4.502841 
 1915  4.60094 
 1916 4.612984 
 1917 4.634109 
 1918 4.683754 
 1919 4.641488 
 1920 4.674042 
 1921 4.674391 
 1922 4.695918 
 1923 4.692993 
 1924 4.682241 
 1925 4.697364 
 1926 4.700102 
 1927 4.747448 
 1928   4.7664 
 1929 4.695027 
 1930 4.657528 
 1931 4.677572 
 1932 4.718922 
 1933 4.660955 
 1934 4.628385 
 1935 4.719622 
 1936 4.797447 
 1937 4.779299 
 1938 4.795784 
 1939 4.768521 
 1940  4.76639 
 1941 4.771522 
 1942 4.776299 
 1943 4.775842 
 1944 4.808623 
 1945   4.7808 
 1946 4.748858 
 1947 4.781907 
 1948 4.796838 
 1949 4.853768 
 1950 4.790714 
 1951 4.805373 
 1952  4.78784 
 1953  4.74692 
 1954 4.752659 
 1955 4.776299 
 1956 4.800963 
 1957 4.788425 
 1958 4.775821 
 1959 4.779611 
 1960 4.829866 
 1961 4.774839 
 1962 4.741757 
 1963 4.642717 
 1964 4.498015 
 1965 4.568669 
 1966  4.62835 
 1967 4.667966 
 1968 4.624649 
 1969 4.607594 
 1970 4.675132 
 1971 4.763645 
 1972 4.797132 
 1973  4.79613 
 1974 4.787076 
 1975 4.761377 
 1976 4.825674 
 1977 4.828514 
 1978 4.890768 
 1979 4.922003 
 1980 5.010267 
 1981 5.020752 
 1982 4.866027 
 1983 4.690964 
 1984 4.880401 
 1985  4.94614 
 1986  4.96056 
 1987 5.024423 
 1988 5.096569 
 1989 5.149953 
 1990  5.17788 
 1991 5.139607 
 1992 4.737895 
 1993  4.94174 
 1994 5.045381 
 1995 5.098622 
 1996 5.214977 
 1997 5.298747 
 1998  5.35397 
 1999 5.366206 
 2000  5.40831 
 2001 5.486541 
 2002 5.517394 
 2003 5.493773 
 2004 5.506724 
 2005 5.555368