# year    value 
 1980 0.4994562 
 1981 0.4095462 
 1982 0.2800918 
 1983 0.2433867 
 1984 0.3500642 
 1985 0.2744823 
 1986 0.3441079 
 1987 0.4876948 
 1988 0.5365472 
 1989 0.6345109 
 1990 0.6933899 
 1991 0.3493535 
 1992 0.2921687 
 1993 0.4035171 
 1994 0.4114908 
 1995 0.4994631 
 1996 0.6793236 
 1997 0.6973273 
 1998 0.7239002 
 1999 0.7743757 
 2000 0.8279017 
 2001 1.006762 
 2002 0.9302713 
 2003 0.8511782 
 2004 0.8699583 
 2005 1.011549