# year    value 
 1900  10.3793 
 1901  10.4389 
 1902 10.26094 
 1903 9.423857 
 1904 9.855502 
 1905 10.15698 
 1906 10.27616 
 1907 10.11626 
 1908 10.28907 
 1909 10.19759 
 1910 10.27875 
 1911 10.28301 
 1912 9.954107 
 1913 9.999123 
 1914 10.22408 
 1915 10.15341 
 1916 10.31259 
 1917 10.38498 
 1918 10.39709 
 1919 10.41759 
 1920 10.17761 
 1921 10.35317 
 1922 10.48794 
 1923 10.44271 
 1924 10.43824 
 1925 10.52961 
 1926 10.32788 
 1927 10.40336 
 1928 10.37787 
 1929 10.44634 
 1930 10.34073 
 1931 10.35459 
 1932 10.24738 
 1933 10.49891 
 1934 10.33899 
 1935 10.38011 
 1936 10.28583 
 1937 10.59579 
 1938 10.43754 
 1939 10.42858 
 1940 10.58503 
 1941 10.45297 
 1942 10.41216 
 1943 10.46043 
 1944  10.4279 
 1945 10.32769 
 1946 10.51528 
 1947 10.54954 
 1948 10.44915 
 1949 10.61223 
 1950 10.67751 
 1951 10.52838 
 1952 10.52066 
 1953 10.57144 
 1954 10.40133 
 1955 10.53724 
 1956 10.54505 
 1957 10.41424 
 1958  10.2429 
 1959 10.38612 
 1960 10.37696 
 1961 10.39455 
 1962 10.36892 
 1963 10.37632 
 1964 10.13296 
 1965 10.05292 
 1966  10.2234 
 1967  10.2991 
 1968 10.25544 
 1969  10.1579 
 1970 10.27953 
 1971  10.4772 
 1972 10.43002 
 1973 10.45748 
 1974 10.33787 
 1975 10.20107 
 1976 10.54605 
 1977 10.60466 
 1978 10.68919 
 1979 10.64499 
 1980 10.71795 
 1981 10.94016 
 1982 10.51888 
 1983 10.15903 
 1984 10.58942 
 1985 10.73848 
 1986 10.86283 
 1987 10.67725 
 1988 10.85242 
 1989 10.99582 
 1990 10.94714 
 1991 11.03903 
 1992 10.27007 
 1993 10.52537 
 1994 11.00664 
 1995 10.88702 
 1996 11.01546 
 1997 11.10134 
 1998  11.4655 
 1999 11.25123 
 2000  11.4576 
 2001 11.43771 
 2002 11.48356 
 2003 11.58347 
 2004 11.57009 
 2005 11.44592