# year    value 
 1900 3.673719 
 1901 3.588588 
 1902 3.611458 
 1903 3.324368 
 1904  3.37803 
 1905 3.468455 
 1906 3.508377 
 1907  3.58545 
 1908 3.559613 
 1909 3.602431 
 1910 3.629968 
 1911 3.642229 
 1912 3.665921 
 1913 3.524814 
 1914 3.617811 
 1915 3.703311 
 1916 3.757596 
 1917  3.72609 
 1918 3.699944 
 1919  3.67983 
 1920 3.782563 
 1921 3.770585 
 1922 3.829093 
 1923 3.776703 
 1924 3.786284 
 1925 3.809131 
 1926  3.77995 
 1927 3.814293 
 1928 3.825236 
 1929 3.759829 
 1930 3.726085 
 1931   3.7705 
 1932 3.802001 
 1933 3.732492 
 1934 3.722399 
 1935 3.834095 
 1936 3.898358 
 1937 3.813909 
 1938 3.855156 
 1939  3.91745 
 1940 3.826619 
 1941 3.830524 
 1942 3.912125 
 1943 3.910473 
 1944 3.900326 
 1945 3.861766 
 1946 3.840579 
 1947 3.862673 
 1948 3.916363 
 1949 3.945182 
 1950 3.879247 
 1951 3.882481 
 1952 3.876357 
 1953 3.866353 
 1954  3.86935 
 1955 3.881335 
 1956 3.897183 
 1957  3.86172 
 1958 3.934798 
 1959 3.921906 
 1960 3.925756 
 1961 3.866573 
 1962 3.811313 
 1963 3.756398 
 1964 3.616013 
 1965 3.637544 
 1966 3.718593 
 1967 3.720109 
 1968  3.70422 
 1969 3.727093 
 1970 3.818396 
 1971 3.901863 
 1972  3.91998 
 1973 3.924807 
 1974  3.89418 
 1975 3.930102 
 1976 3.941415 
 1977 3.948019 
 1978 3.985346 
 1979  4.00914 
 1980 4.119974 
 1981 4.091438 
 1982 3.911843 
 1983 3.831205 
 1984 3.994576 
 1985 3.944861 
 1986 4.010529 
 1987 4.142299 
 1988 4.185066 
 1989 4.213456 
 1990  4.29247 
 1991 4.182835 
 1992 3.901101 
 1993 4.054501 
 1994 4.013937 
 1995 4.155398 
 1996 4.302146 
 1997 4.384704 
 1998  4.39215 
 1999 4.424167 
 2000  4.41731 
 2001 4.519935 
 2002 4.574814 
 2003 4.502167 
 2004 4.530258 
 2005  4.64887