# year    value 
 1960 -0.3827965 
 1961 -0.3753904 
 1962 -0.4368523 
 1963 -0.563663 
 1964 -0.7074268 
 1965 -0.5949404 
 1966 -0.5779644 
 1967 -0.5513764 
 1968 -0.5603143 
 1969 -0.5610841 
 1970 -0.4867315 
 1971 -0.3809129 
 1972 -0.3668037 
 1973 -0.3611635 
 1974 -0.39258 
 1975 -0.3610452 
 1976 -0.2916719 
 1977 -0.3181555 
 1978 -0.3190994 
 1979 -0.2479604 
 1980 -0.1167074 
 1981 -0.1841463 
 1982 -0.2776469 
 1983 -0.3835494 
 1984 -0.2614683 
 1985 -0.3379216 
 1986 -0.2555288 
 1987 -0.1060048 
 1988 -0.08258982 
 1989 -0.0696599 
 1990 0.0101571 
 1991 -0.1635201 
 1992 -0.362826 
 1993 -0.2312158 
 1994 -0.2468229 
 1995 -0.1870103 
 1996 0.03522022 
 1997 0.04442445 
 1998 0.1042288 
 1999 0.1342206 
 2000 0.1287871 
 2001 0.2540629 
 2002 0.3094581 
 2003 0.1678566 
 2004 0.2187846 
 2005 0.1338335