# year    value 
 1980 1.075069 
 1981 1.069272 
 1982 0.9396361 
 1983 0.7531303 
 1984 0.8841527 
 1985 0.9946858 
 1986 0.9041596 
 1987 0.9666874 
 1988 1.141422 
 1989 1.136261 
 1990 1.176615 
 1991 1.231981 
 1992 0.6494983 
 1993 0.858611 
 1994 1.021248 
 1995  1.08864 
 1996 1.202382 
 1997 1.269495 
 1998 1.352813 
 1999 1.315831 
 2000 1.353866 
 2001 1.409174 
 2002 1.553236 
 2003 1.500564 
 2004 1.521515 
 2005 1.502526