# year    value 
 1980 0.2593756 
 1981 0.3246429 
 1982 0.002821732 
 1983 -0.06975748 
 1984 0.1426487 
 1985 0.335285 
 1986 0.2827555 
 1987 0.4077227 
 1988 0.4723343 
 1989 0.5830396 
 1990 0.2554919 
 1991 0.2642122 
 1992 -0.2644252 
 1993 0.3266859 
 1994 0.6601331 
 1995 0.5093737 
 1996 0.4398262 
 1997 0.8582783 
 1998 0.7288172 
 1999 0.7208283 
 2000 0.9892383 
 2001 0.8355725 
 2002 1.006149 
 2003 1.035079 
 2004 1.037532 
 2005 0.840947