# year    value 
 1980 0.8260499 
 1981 0.8334505 
 1982 0.9276342 
 1983 0.4892451 
 1984 0.7756802 
 1985 0.8509044 
 1986 0.8006049 
 1987 0.7178426 
 1988 0.9773104 
 1989 1.021461 
 1990 0.9463037 
 1991 1.119283 
 1992 0.4492939 
 1993 0.5167055 
 1994 0.866177 
 1995 0.9063139 
 1996 1.142192 
 1997 1.060146 
 1998 1.143189 
 1999 1.086978 
 2000 1.303405 
 2001 1.185073 
 2002 1.363654 
 2003 1.324163 
 2004 1.532506 
 2005 1.273008