# year    value 
 1980 0.4365803 
 1981 0.3532123 
 1982 0.2108769 
 1983 0.1668099 
 1984 0.2847014 
 1985 0.2175299 
 1986 0.2699709 
 1987 0.4212639 
 1988 0.4584325 
 1989 0.5676868 
 1990 0.605951 
 1991 0.269177 
 1992 0.2155014 
 1993 0.3269363 
 1994 0.3542722 
 1995 0.4466904 
 1996 0.5980679 
 1997 0.6362758 
 1998 0.6680996 
 1999 0.7082818 
 2000 0.7639235 
 2001 0.9300268 
 2002 0.8634779 
 2003 0.795386 
 2004 0.8208475 
 2005 0.9524199