# year    value 
 1980 -12.57927 
 1981 -12.32782 
 1982 -12.37291 
 1983 -12.79837 
 1984 -12.59254 
 1985 -12.76361 
 1986 -12.56022 
 1987 -12.38469 
 1988 -12.39046 
 1989 -12.33326 
 1990 -12.08039 
 1991 -12.11417 
 1992 -12.51532 
 1993 -12.54822 
 1994 -12.51118 
 1995 -12.26299 
 1996 -12.12934 
 1997 -12.22151 
 1998 -12.02466 
 1999 -12.24795 
 2000 -11.97006 
 2001 -11.87888 
 2002 -11.83916 
 2003 -11.5971 
 2004 -11.66404 
 2005 -11.67221