# year    value 
 1980 -1.541038 
 1981 -1.522816 
 1982 -1.337199 
 1983 -1.603805 
 1984 -1.585595 
 1985 -1.56722 
 1986 -1.419375 
 1987 -1.330796 
 1988 -1.285487 
 1989 -1.199694 
 1990 -1.108837 
 1991 -1.285135 
 1992 -1.441318 
 1993 -1.593647 
 1994 -1.433799 
 1995 -1.122743 
 1996 -1.375656 
 1997 -1.109621 
 1998 -1.109017 
 1999 -0.9702901 
 2000 -0.6707523 
 2001 -0.8045768 
 2002 -0.985423 
 2003 -0.728197 
 2004 -0.9292528 
 2005 -1.062171