# year    value 
 1940 -0.461926 
 1941 -0.4080553 
 1942 -0.4279309 
 1943 -0.4553721 
 1944 -0.4236559 
 1945 -0.4026186 
 1946 -0.4690642 
 1947 -0.457949 
 1948 -0.4268484 
 1949 -0.3494868 
 1950 -0.4560744 
 1951 -0.4021596 
 1952 -0.4730205 
 1953 -0.4283628 
 1954 -0.4048354 
 1955 -0.4324545 
 1956 -0.380862 
 1957 -0.3964143 
 1958 -0.4094145 
 1959 -0.3876755 
 1960 -0.3925718 
 1961 -0.3906229 
 1962 -0.4505311 
 1963 -0.5776411 
 1964 -0.7394454 
 1965 -0.622593 
 1966 -0.5997842 
 1967 -0.5667288 
 1968 -0.5670372 
 1969 -0.5729109 
 1970 -0.4956503 
 1971 -0.3924987 
 1972 -0.3829592 
 1973 -0.3701483 
 1974 -0.4088938 
 1975 -0.3843325 
 1976 -0.3142878 
 1977 -0.3366529 
 1978 -0.3178332 
 1979 -0.257741 
 1980 -0.1312562 
 1981 -0.1842188 
 1982 -0.2878085 
 1983 -0.4022722 
 1984 -0.2650089 
 1985 -0.3393967 
 1986 -0.2631818 
 1987 -0.1163483 
 1988 -0.08612638 
 1989 -0.07329814 
 1990 0.00275523 
 1991 -0.1681361 
 1992 -0.3775768 
 1993 -0.2386667 
 1994 -0.2523803 
 1995 -0.180188 
 1996 0.0333493 
 1997 0.04834999 
 1998 0.1023069 
 1999 0.1405433 
 2000 0.1335613 
 2001 0.2585124 
 2002 0.3057675 
 2003 0.1798963 
 2004 0.2341582 
 2005 0.1331524