# year    value 
 1980 -0.2745996 
 1981 -0.1897837 
 1982 -0.3272454 
 1983 -0.5767645 
 1984 -0.3485853 
 1985 -0.3159489 
 1986 -0.2711295 
 1987 -0.2384191 
 1988 -0.1182802 
 1989 -0.07648808 
 1990 -0.06182167 
 1991 -0.08351602 
 1992 -0.5550354 
 1993 -0.3764961 
 1994 -0.2177848 
 1995 -0.09165553 
 1996 0.03533799 
 1997 0.03868813 
 1998 0.08795038 
 1999 0.1125999 
 2000 0.221012 
 2001 0.2599106 
 2002 0.3064068 
 2003 0.3104898 
 2004 0.3485934 
 2005 1.349782