# year    value 
 1980 -0.1826773 
 1981 -0.1307039 
 1982 -0.2245335 
 1983 -0.3303723 
 1984 -0.2165764 
 1985 -0.1635664 
 1986 -0.2110096 
 1987 -0.1710151 
 1988 -0.08465114 
 1989 -0.02870012 
 1990 -0.02958902 
 1991 -0.07212226 
 1992 -0.2951371 
 1993 -0.1955327 
 1994 -0.1457232 
 1995 -0.07991126 
 1996 -0.03741666 
 1997 0.04550819 
 1998 0.0967144 
 1999 0.1069541 
 2000 0.09216728 
 2001 0.1923958 
 2002 0.2353736 
 2003 0.1974265 
 2004 0.1680212 
 2005 -0.1588946