# year    value 
 1980 -1.926563 
 1981 -2.022842 
 1982 -2.181412 
 1983 -2.182104 
 1984 -1.982811 
 1985 -2.180091 
 1986 -2.019373 
 1987 -1.751047 
 1988 -1.915732 
 1989 -1.702112 
 1990 -1.563991 
 1991 -1.718851 
 1992 -1.768374 
 1993 -1.787867 
 1994 -1.903855 
 1995 -1.923283 
 1996 -1.777478 
 1997 -1.533845 
 1998  -1.3931 
 1999 -1.457247 
 2000 -1.202431 
 2001 -0.9417263 
 2002 -1.155559 
 2003 -1.219764 
 2004 -1.272394 
 2005 -0.8864163