# year    value 
 1960 -0.8665681 
 1961 -0.8722169 
 1962 -0.8730784 
 1963 -0.9527413 
 1964 -1.050206 
 1965 -1.11914 
 1966 -1.040477 
 1967 -0.9910187 
 1968 -1.046475 
 1969 -0.9396494 
 1970 -0.9485459 
 1971 -0.9028679 
 1972 -0.82223 
 1973 -0.8225108 
 1974 -0.7976024 
 1975 -0.8027449 
 1976 -0.8323708 
 1977 -0.7851667 
 1978 -0.6260691 
 1979 -0.5281922 
 1980 -0.5107787 
 1981 -0.4185696 
 1982 -0.6536686 
 1983 -0.8380732 
 1984 -0.680797 
 1985 -0.5516892 
 1986 -0.6024845 
 1987 -0.3324626 
 1988 -0.3172479 
 1989 -0.2991907 
 1990 -0.1104346 
 1991 -0.1876517 
 1992 -0.4121091 
 1993 -0.3558667 
 1994 -0.3198997 
 1995 -0.2744603 
 1996 -0.1370728 
 1997 0.03858766 
 1998 0.1319224 
 1999 0.2175708 
 2000 0.2927716 
 2001 0.4391905 
 2002 0.4461902 
 2003 0.5044477 
 2004 0.514851 
 2005 1.974341