# year    value 
 1980 -0.1683774 
 1981 -0.1844039 
 1982 -0.3137357 
 1983 -0.4500432 
 1984 -0.2740428 
 1985 -0.3431604 
 1986 -0.2827081 
 1987 -0.1427394 
 1988 -0.09514981 
 1989 -0.08258097 
 1990 -0.01613048 
 1991 -0.1799139 
 1992 -0.4152131 
 1993 -0.2576775 
 1994 -0.2665598 
 1995 -0.162781 
 1996 0.02857564 
 1997 0.05836596 
 1998 0.0974033 
 1999 0.1566757 
 2000 0.1457426 
 2001 0.2698653 
 2002 0.2963512 
 2003 0.2106153 
 2004 0.2733837 
 2005 0.1314148