# year    value 
 1980 -0.1505723 
 1981 -0.1177917 
 1982 -0.206347 
 1983 -0.2905083 
 1984 -0.199289 
 1985 -0.1677764 
 1986 -0.1826069 
 1987 -0.1460947 
 1988 -0.09834147 
 1989 -0.04163187 
 1990 -0.03044169 
 1991 -0.07405693 
 1992 -0.2832814 
 1993 -0.1965431 
 1994 -0.1191503 
 1995 -0.07477171 
 1996 -0.01620744 
 1997 0.03757444 
 1998 0.0798235 
 1999 0.09307501 
 2000 0.09473584 
 2001 0.1773663 
 2002 0.2039664 
 2003 0.1948002 
 2004 0.1514574 
 2005 -0.09378461