# year    value 
 1980 -0.4794064 
 1981 -0.2451872 
 1982 -0.3736071 
 1983 -0.6344209 
 1984 -0.5218358 
 1985 -0.4651648 
 1986 -0.2992436 
 1987 -0.2805649 
 1988 -0.1754541 
 1989 -0.05831418 
 1990 0.002601335 
 1991 -0.2897618 
 1992 -0.4039089 
 1993 -0.4962846 
 1994 -0.2259093 
 1995 -0.03066458 
 1996 -0.06480318 
 1997 0.08150555 
 1998 0.06339915 
 1999 0.1125258 
 2000 0.3020179 
 2001 0.3594646 
 2002 0.2680402 
 2003 0.464059 
 2004 0.3373924 
 2005 0.9428115