Year	Years
1970	0.9257
1971	0.906
1972	0.6123
1973	0.3954
1974	0.2051
1975	0.2535
1976	-0.6009
1977	-0.7024
1978	-1.403
1979	-0.997
1980	-1.605
1981	-2.737
1982	-3.021
1983	-2.579
1984	-2.524
1985	-2.379
1986	-1.772
1987	-2.12
1988	-1.922
1989	-2.336
1990	-2.456
1991	-1.193
1992	-1.454
1993	-1.478
1994	-1.672
1995	-1.665
1996	-1.435
1997	-1.026
1998	-0.9479
1999	-1.601
2000	-1.071
2001	-1.162
2002	-1.886
2003	-1.393
2004	-1.196