# year    value 
 1980 -2.802594 
 1981 -2.940897 
 1982 -2.927867 
 1983 -3.025877 
 1984 -2.955786 
 1985 -3.052317 
 1986 -2.946046 
 1987 -2.744086 
 1988 -2.794694 
 1989 -2.74492 
 1990 -2.636256 
 1991 -2.828078 
 1992 -3.063514 
 1993 -2.872713 
 1994 -2.90519 
 1995 -2.862349 
 1996 -2.540637 
 1997 -2.659895 
 1998 -2.415237 
 1999 -2.48621 
 2000 -2.546378 
 2001 -2.443115 
 2002 -2.29746 
 2003 -2.496686 
 2004 -2.31793 
 2005 -2.366117