# year    value 
 1960 -0.4031738 
 1961 -0.4216551 
 1962 -0.4259283 
 1963 -0.5312101 
 1964 -0.6617498 
 1965 -0.6343118 
 1966 -0.5746596 
 1967 -0.5359904 
 1968 -0.5890658 
 1969 -0.5673246 
 1970 -0.4998911 
 1971 -0.4013587 
 1972 -0.3741577 
 1973 -0.3425083 
 1974 -0.3942222 
 1975 -0.3832868 
 1976 -0.3528671 
 1977 -0.3442781 
 1978 -0.3234954 
 1979 -0.2585793 
 1980 -0.1890031 
 1981 -0.1681406 
 1982 -0.3677922 
 1983 -0.4590566 
 1984 -0.3158014 
 1985 -0.2843809 
 1986 -0.2610683 
 1987 -0.1795381 
 1988 -0.100799 
 1989 -0.06778826 
 1990 -0.02542231 
 1991 -0.1226023 
 1992 -0.4580822 
 1993 -0.2795064 
 1994 -0.2100029 
 1995 -0.107416 
 1996 -0.001503574 
 1997 0.06919787 
 1998 0.1070491 
 1999 0.1209353 
 2000 0.1624775 
 2001 0.228432 
 2002 0.2818628 
 2003 0.2521245 
 2004 0.2450613 
 2005 0.8637112