# year    value 
 1980 -0.1953768 
 1981 -0.178796 
 1982 -0.3316619 
 1983 -0.4269203 
 1984 -0.308674 
 1985 -0.2664052 
 1986 -0.2474017 
 1987 -0.1718565 
 1988 -0.08960971 
 1989 -0.06431182 
 1990 -0.02684646 
 1991 -0.1312572 
 1992 -0.4110336 
 1993 -0.2588776 
 1994 -0.2041869 
 1995 -0.1214085 
 1996 -0.01811857 
 1997 0.05292053 
 1998 0.08723194 
 1999 0.1258209 
 2000 0.1436638 
 2001 0.2329337 
 2002 0.2757359 
 2003 0.2440481 
 2004 0.2559407 
 2005 0.6980689