# year    value 
 1960 -0.4767304 
 1961 -0.4934897 
 1962 -0.5275823 
 1963 -0.6215335 
 1964 -0.7658535 
 1965 -0.7109914 
 1966 -0.6680388 
 1967 -0.6345106 
 1968 -0.652228 
 1969 -0.6617937 
 1970 -0.6035969 
 1971 -0.5192605 
 1972 -0.4782022 
 1973 -0.4810197 
 1974 -0.4921239 
 1975 -0.4923201 
 1976 -0.4625565 
 1977 -0.4487736 
 1978 -0.3745013 
 1979 -0.3188289 
 1980 -0.26546 
 1981 -0.2159315 
 1982 -0.3725419 
 1983 -0.524686 
 1984 -0.3790404 
 1985 -0.3319361 
 1986 -0.3214125 
 1987 -0.2179288 
 1988 -0.1444353 
 1989 -0.1052024 
 1990 -0.03578775 
 1991 -0.1225211 
 1992 -0.4324983 
 1993 -0.2995489 
 1994 -0.2009438 
 1995 -0.1362181 
 1996 -0.04335975 
 1997 0.05322382 
 1998 0.09371276 
 1999 0.1306719 
 2000 0.1869677 
 2001 0.2653386 
 2002 0.3128857 
 2003 0.3089178 
 2004 0.3110535 
 2005 0.8555482