# year    value 
 1900 12.20816 
 1901 12.26591 
 1902 12.14379 
 1903  11.5472 
 1904 11.79039 
 1905 12.02896 
 1906 12.08742 
 1907 11.99646 
 1908 12.07344 
 1909 12.09904 
 1910 12.10639 
 1911 12.10764 
 1912 11.87956 
 1913 11.84304 
 1914 12.02493 
 1915 12.19103 
 1916  12.2111 
 1917 12.26332 
 1918 12.30258 
 1919 12.30504 
 1920 12.20168 
 1921 12.21551 
 1922 12.31113 
 1923 12.26173 
 1924 12.30574 
 1925 12.33099 
 1926 12.30249 
 1927 12.32955 
 1928 12.34284 
 1929  12.2948 
 1930 12.27321 
 1931 12.28619 
 1932 12.29893 
 1933  12.3026 
 1934 12.32147 
 1935 12.26567 
 1936 12.30845 
 1937 12.39038 
 1938 12.36839 
 1939 12.30078 
 1940 12.41196 
 1941 12.33278 
 1942  12.3009 
 1943 12.27946 
 1944  12.2979 
 1945 12.30078 
 1946 12.35453 
 1947 12.33412 
 1948 12.34523 
 1949 12.45621 
 1950 12.42142 
 1951 12.42878 
 1952 12.37396 
 1953 12.35501 
 1954  12.2873 
 1955 12.38395 
 1956 12.33239 
 1957 12.32121 
 1958 12.31247 
 1959   12.304 
 1960 12.34315 
 1961 12.26694 
 1962 12.21149 
 1963 12.14264 
 1964 12.03151 
 1965 12.02348 
 1966 12.09984 
 1967 12.16515 
 1968 12.05805 
 1969 12.02065 
 1970 12.16697 
 1971 12.24531 
 1972 12.29173 
 1973 12.28195 
 1974 12.32834 
 1975 12.15384 
 1976 12.31322 
 1977 12.38973 
 1978 12.48331 
 1979 12.50972 
 1980 12.53329 
 1981 12.62794 
 1982 12.41098 
 1983 12.06874 
 1984 12.37577 
 1985 12.55488 
 1986 12.57713 
 1987 12.52315 
 1988 12.66739 
 1989 12.75953 
 1990  12.7311 
 1991 12.76948 
 1992 12.14097 
 1993 12.40026 
 1994 12.70725 
 1995 12.75921 
 1996 12.76385 
 1997 12.90142 
 1998 13.05664 
 1999 13.01854 
 2000 13.16331 
 2001 13.23998 
 2002 13.15559 
 2003 13.26012 
 2004 13.26019 
 2005 13.25035