# year    value 
 1980 -4.82009 
 1981 -4.832653 
 1982 -4.883495 
 1983 -4.922504 
 1984 -4.880731 
 1985 -4.851012 
 1986 -4.882108 
 1987 -4.83992 
 1988 -4.800061 
 1989 -4.70952 
 1990 -4.730647 
 1991 -4.715802 
 1992 -4.961768 
 1993 -4.882564 
 1994 -4.792193 
 1995 -4.735452 
 1996 -4.64108 
 1997 -4.669336 
 1998 -4.566823 
 1999 -4.557902 
 2000 -4.608737 
 2001 -4.529939 
 2002 -4.500869 
 2003 -4.490522 
 2004 -4.559791 
 2005 -4.488986