Year	Years
1970	1.885
1971	2.316
1972	1.862
1973	1.949
1974	2.17
1975	2.401
1976	2.776
1977	1.484
1978	1.051
1979	0.6441
1980	1.237
1981	0.8634
1982	0.164
1983	-0.7599
1984	-1.68
1985	-3.097
1986	-3.204
1987	-2.04
1988	-0.8597
1989	-0.08258
1990	-0.1554
1991	-0.4756
1992	-0.9576
1993	0.2898
1994	1.274
1995	0.6826
1996	0.9885
1997	1.05
1998	0.7585
1999	-0.4646
2000	-0.1994
2001	1.4
2002	2.909
2003	3.394