# year    value 
 1980 -0.2270036 
 1981 -0.2308097 
 1982 -0.3546114 
 1983 -0.5537022 
 1984 -0.3441228 
 1985 -0.442225 
 1986 -0.3211823 
 1987 -0.2038015 
 1988 -0.1706285 
 1989 -0.1900393 
 1990 -0.1306934 
 1991 -0.1372145 
 1992 -0.4943739 
 1993 -0.3537019 
 1994 -0.3449533 
 1995 -0.3562222 
 1996 -0.1132796 
 1997 -0.07602294 
 1998 -0.07608432 
 1999 0.04032629 
 2000 -0.01052193 
 2001 0.1257947 
 2002 0.2237783 
 2003 0.05695435 
 2004 0.004822018 
 2005 0.1359182