# year    value 
 1900 11.49999 
 1901 11.52734 
 1902 11.41518 
 1903 10.91477 
 1904 11.10259 
 1905 11.34466 
 1906 11.38995 
 1907 11.30516 
 1908 11.38744 
 1909 11.39217 
 1910  11.3921 
 1911 11.39164 
 1912 11.19538 
 1913  11.1333 
 1914 11.30307 
 1915 11.45603 
 1916  11.4732 
 1917 11.53275 
 1918 11.60909 
 1919 11.56138 
 1920 11.49277 
 1921 11.52884 
 1922 11.59054 
 1923 11.56334 
 1924 11.55869 
 1925 11.58309 
 1926 11.59052 
 1927  11.6243 
 1928 11.64398 
 1929 11.53961 
 1930  11.5225 
 1931 11.54832 
 1932 11.60507 
 1933 11.55002 
 1934 11.55081 
 1935 11.53665 
 1936 11.61529 
 1937 11.66942 
 1938 11.65765 
 1939    11.61 
 1940 11.66711 
 1941 11.61489 
 1942 11.59382 
 1943  11.5495 
 1944   11.614 
 1945 11.60469 
 1946 11.62402 
 1947 11.63129 
 1948 11.59909 
 1949 11.73576 
 1950 11.67088 
 1951 11.66818 
 1952 11.64055 
 1953 11.62198 
 1954 11.55556 
 1955 11.63562 
 1956 11.61624 
 1957 11.59753 
 1958 11.59129 
 1959 11.58347 
 1960 11.66415 
 1961 11.56248 
 1962  11.5072 
 1963 11.43548 
 1964 11.30422 
 1965 11.33105 
 1966  11.3864 
 1967 11.44483 
 1968 11.34313 
 1969 11.29921 
 1970 11.44055 
 1971 11.49482 
 1972 11.55739 
 1973 11.54764 
 1974 11.58611 
 1975 11.45749 
 1976 11.58521 
 1977 11.63573 
 1978 11.71202 
 1979 11.73615 
 1980 11.79161 
 1981  11.8874 
 1982 11.65753 
 1983 11.35974 
 1984 11.68593 
 1985 11.81194 
 1986 11.82846 
 1987 11.83866 
 1988 11.92745 
 1989 12.03849 
 1990 11.98548 
 1991 12.05242 
 1992 11.42412 
 1993 11.68421 
 1994 11.98842 
 1995 12.02986 
 1996 12.05644 
 1997 12.20472 
 1998  12.3122 
 1999 12.26874 
 2000 12.42413 
 2001 12.46082 
 2002  12.4386 
 2003  12.5058 
 2004 12.49842 
 2005 12.51007