# year    value 
 1980 -0.4461834 
 1981 -0.3904183 
 1982 -0.4843119 
 1983 -0.7192464 
 1984 -0.5373617 
 1985 -0.5407469 
 1986 -0.5388086 
 1987 -0.4267946 
 1988 -0.3352077 
 1989 -0.2922201 
 1990 -0.2151106 
 1991 -0.2251587 
 1992 -0.6152205 
 1993 -0.4733714 
 1994 -0.3818252 
 1995 -0.368582 
 1996 -0.2636664 
 1997 -0.1588507 
 1998 -0.1119148 
 1999 -0.07532788 
 2000 -0.03848349 
 2001 0.06550622 
 2002 0.07502759 
 2003 0.0519779 
 2004 0.07230893 
 2005 0.1680681