# year    value 
 1980 -1.579774 
 1981 -1.567773 
 1982 -1.333268 
 1983 -1.647404 
 1984 -1.597215 
 1985 -1.622927 
 1986 -1.455899 
 1987 -1.325754 
 1988 -1.314538 
 1989 -1.240042 
 1990 -1.160298 
 1991 -1.284799 
 1992 -1.479437 
 1993 -1.644725 
 1994 -1.478673 
 1995 -1.152562 
 1996 -1.410053 
 1997 -1.151802 
 1998 -1.095134 
 1999 -0.9922479 
 2000 -0.6759877 
 2001 -0.8179944 
 2002 -1.019054 
 2003 -0.7619885 
 2004 -0.9590526 
 2005 -1.06583