# year    value 
 1980 -0.1944333 
 1981 -0.1772186 
 1982 -0.3370103 
 1983 -0.4316775 
 1984 -0.3097291 
 1985 -0.2690662 
 1986 -0.2494248 
 1987 -0.1729936 
 1988 -0.09126609 
 1989 -0.06482648 
 1990 -0.02663564 
 1991 -0.1299759 
 1992 -0.4179983 
 1993 -0.2619313 
 1994 -0.2050479 
 1995 -0.1193371 
 1996 -0.015659 
 1997 0.05533013 
 1998 0.09016552 
 1999 0.1250977 
 2000 0.1464488 
 2001 0.2322673 
 2002 0.2766429 
 2003 0.2452436 
 2004 0.2543302 
 2005 0.7225893