Year	Years
1970	1.472
1971	2.137
1972	1.624
1973	1.392
1974	-0.01859
1975	0.4317
1976	0.4999
1977	-0.03646
1978	-0.7566
1979	-0.7068
1980	-0.09817
1981	-0.0661
1982	-0.7624
1983	-1.102
1984	-1.011
1985	-1.438
1986	-1.903
1987	-1.585
1988	-1.393
1989	-1.451
1990	-1.345
1991	-0.7412
1992	-0.7562
1993	-0.3898
1994	-0.7201
1995	-0.3545
1996	-0.09071
1997	4.545
1998	4.911
1999	5.197
2000	5.065
2001	5.114
2002	6.063
2003	6.348