# year    value 
 1980 10.85659 
 1981 11.05459 
 1982  10.6975 
 1983 10.40167 
 1984 10.84508 
 1985 10.83363 
 1986 10.99728 
 1987 11.03333 
 1988  11.0299 
 1989 11.24015 
 1990 11.05439 
 1991 11.31899 
 1992 10.45375 
 1993 10.60481 
 1994 11.18834 
 1995 11.18236 
 1996 11.20835 
 1997 11.31184 
 1998 11.55298 
 1999 11.40665 
 2000 11.69463 
 2001 11.50522 
 2002 11.55667 
 2003 11.81526 
 2004 11.66294 
 2005 11.62205