# year    value 
 1900 4.669733 
 1901 4.144542 
 1902 4.193696 
 1903  3.98203 
 1904 3.970318 
 1905 4.036752 
 1906 4.193124 
 1907 4.163001 
 1908 4.214782 
 1909 4.229758 
 1910 4.261362 
 1911  4.20046 
 1912 4.224668 
 1913 4.207635 
 1914 4.275927 
 1915 4.211216 
 1916 4.229904 
 1917  4.32361 
 1918 4.361187 
 1919 4.290327 
 1920 4.285341 
 1921 4.265887 
 1922 4.235212 
 1923 4.304287 
 1924 4.326643 
 1925 4.304738 
 1926  4.35622 
 1927 4.278626 
 1928 4.337886 
 1929  4.32886 
 1930  4.34961 
 1931 4.309568 
 1932 4.341334 
 1933 4.286217 
 1934 4.347136 
 1935 4.338643 
 1936 4.291889 
 1937 4.382132 
 1938 4.347826 
 1939  4.45206 
 1940 4.451481 
 1941 4.397485 
 1942 4.401814 
 1943 4.342149 
 1944 4.415292 
 1945 4.378639 
 1946 4.358555 
 1947 4.392236 
 1948 4.427832 
 1949 4.444849 
 1950 4.429475 
 1951 4.446316 
 1952 4.371653 
 1953 4.442423 
 1954 4.461299 
 1955 4.423484 
 1956 4.425774 
 1957 4.477577 
 1958 4.483013 
 1959 4.428245 
 1960 4.446025 
 1961 4.476259 
 1962 4.451559 
 1963 4.387987 
 1964 4.156703 
 1965 4.238733 
 1966 4.291911 
 1967 4.343054 
 1968 4.380867 
 1969 4.376261 
 1970 4.377769 
 1971 4.480221 
 1972 4.528821 
 1973 4.488554 
 1974 4.484836 
 1975 4.506596 
 1976 4.507056 
 1977 4.565142 
 1978 4.541994 
 1979 4.628096 
 1980 4.536969 
 1981   4.6753 
 1982 4.662371 
 1983 4.447592 
 1984 4.501008 
 1985 4.637207 
 1986 4.566598 
 1987 4.543736 
 1988 4.643298 
 1989 4.649131 
 1990 4.694694 
 1991 4.712236 
 1992 4.470952 
 1993 4.500296 
 1994  4.62903 
 1995 4.682467 
 1996 4.692544 
 1997 4.790478 
 1998 4.822666 
 1999 4.865262 
 2000 4.865331 
 2001 4.951084 
 2002 4.958057 
 2003 4.993226 
 2004 4.924483 
 2005 5.032242