# year    value 
 1980 -4.903419 
 1981 -4.915533 
 1982 -4.971019 
 1983 -5.006798 
 1984 -4.964804 
 1985 -4.932212 
 1986 -4.979362 
 1987 -4.931467 
 1988 -4.882864 
 1989 -4.792707 
 1990 -4.815111 
 1991 -4.802748 
 1992 -5.053505 
 1993 -4.968372 
 1994 -4.882225 
 1995 -4.822967 
 1996 -4.725258 
 1997 -4.748569 
 1998 -4.654025 
 1999 -4.637373 
 2000 -4.703508 
 2001 -4.618599 
 2002 -4.589483 
 2003 -4.57337 
 2004 -4.639751 
 2005 -4.573906