# year    value 
 1980 -0.1951868 
 1981 -0.159538 
 1982 -0.5129734 
 1983 -0.3754476 
 1984 -0.3054315 
 1985 -0.2640477 
 1986 -0.179903 
 1987 -0.1246947 
 1988 -0.1259961 
 1989 0.02275182 
 1990 -0.001632979 
 1991 -0.3154348 
 1992 -0.3656846 
 1993 -0.220961 
 1994 -0.1486589 
 1995 -0.1069178 
 1996 0.03273786 
 1997 0.06837668 
 1998 0.1215887 
 1999 0.1186756 
 2000 0.1854341 
 2001 0.305559 
 2002 0.2331128 
 2003 0.2651312 
 2004 0.2599628 
 2005 0.3747457