# year    value 
 1980 2.056179 
 1981 2.131853 
 1982   2.0094 
 1983 1.854475 
 1984 1.938762 
 1985  1.94074 
 1986 1.921817 
 1987 2.080022 
 1988 2.167911 
 1989 2.047541 
 1990 2.218099 
 1991 2.090847 
 1992 1.865459 
 1993 1.976057 
 1994 1.879015 
 1995 2.025283 
 1996 2.153193 
 1997 2.253777 
 1998 2.255578 
 1999 2.266525 
 2000 2.343785 
 2001 2.314504 
 2002 2.480673 
 2003 2.357249 
 2004 2.392168 
 2005 2.507164