# year    value 
 1980 -0.3508272 
 1981 -0.2603174 
 1982 -0.3724269 
 1983 -0.6552112 
 1984 -0.4362433 
 1985 -0.3768013 
 1986 -0.3057711 
 1987 -0.2875642 
 1988 -0.1292906 
 1989 -0.1019442 
 1990 -0.07756705 
 1991 -0.102344 
 1992 -0.5610439 
 1993 -0.4517345 
 1994 -0.184867 
 1995 -0.1161347 
 1996 -0.02099742 
 1997 0.03740883 
 1998 0.1217819 
 1999 0.06928709 
 2000 0.2637662 
 2001 0.3224052 
 2002 0.3023071 
 2003 0.3931492 
 2004 0.3945682 
 2005 1.499277