# year    value 
 1900 10.54298 
 1901 10.56955 
 1902 10.44675 
 1903 9.823992 
 1904 10.11332 
 1905 10.36747 
 1906 10.52131 
 1907   10.574 
 1908 10.63165 
 1909 10.47346 
 1910  10.5259 
 1911 10.39242 
 1912 10.26734 
 1913 10.13045 
 1914 10.40583 
 1915 10.47055 
 1916 10.54483 
 1917 10.63093 
 1918 10.59338 
 1919 10.71694 
 1920 10.39228 
 1921 10.62093 
 1922 10.75528 
 1923 10.61441 
 1924 10.60477 
 1925 10.74466 
 1926 10.69181 
 1927 10.75035 
 1928 10.62446 
 1929 10.68069 
 1930 10.61943 
 1931 10.59568 
 1932 10.66135 
 1933 10.56972 
 1934 10.58218 
 1935  10.6594 
 1936 10.66383 
 1937 10.80038 
 1938 10.74503 
 1939 10.77792 
 1940 10.79583 
 1941 10.66697 
 1942 10.71012 
 1943  10.5534 
 1944 10.75171 
 1945 10.77059 
 1946 10.79059 
 1947 10.91259 
 1948 10.65449 
 1949 11.08322 
 1950 10.92406 
 1951 10.92306 
 1952 10.80917 
 1953 10.86351 
 1954 10.62269 
 1955 10.82317 
 1956 10.78821 
 1957 10.61671 
 1958 10.61202 
 1959 10.66935 
 1960 10.72462 
 1961  10.7287 
 1962  10.6958 
 1963 10.65564 
 1964 10.47067 
 1965 10.43054 
 1966 10.48736 
 1967 10.66617 
 1968 10.43359 
 1969  10.4069 
 1970 10.57941 
 1971 10.71832 
 1972 10.72806 
 1973 10.70663 
 1974 10.69998 
 1975 10.46859 
 1976  10.7374 
 1977 10.88169 
 1978 10.89453 
 1979 10.93603 
 1980 10.85659 
 1981 11.05459 
 1982  10.6975 
 1983 10.40167 
 1984 10.84508 
 1985 10.83363 
 1986 10.99728 
 1987 11.03333 
 1988  11.0299 
 1989 11.24015 
 1990 11.05439 
 1991 11.31899 
 1992 10.45375 
 1993 10.60481 
 1994 11.18834 
 1995 11.18236 
 1996 11.20835 
 1997 11.31184 
 1998 11.55298 
 1999 11.40665 
 2000 11.69463 
 2001 11.50522 
 2002 11.55667 
 2003 11.81526 
 2004 11.66294 
 2005 11.62205