# year    value 
 1980 -0.3578514 
 1981 -0.2406983 
 1982 -0.3863734 
 1983 -0.65458 
 1984 -0.4524817 
 1985 -0.4025908 
 1986 -0.3443234 
 1987 -0.2792715 
 1988 -0.1903016 
 1989 -0.1063365 
 1990 -0.06378269 
 1991 -0.08572767 
 1992 -0.562551 
 1993 -0.4218297 
 1994 -0.166939 
 1995 -0.09222153 
 1996 -0.05883092 
 1997 0.05813337 
 1998 0.09962864 
 1999 0.1065874 
 2000 0.2620803 
 2001 0.2933648 
 2002 0.3200358 
 2003 0.4045175 
 2004 0.3888848 
 2005 1.414872