Year	Years
1970	6.513
1971	6.97
1972	7.526
1973	8.535
1974	7.493
1975	7.102
1976	8.717
1977	8.348
1978	9.393
1979	9.241
1980	9.01
1981	8.235
1982	7.54
1983	6.197
1984	7.327
1985	6.294
1986	4.578
1987	4.062
1988	2.465
1989	1.071
1990	0.01803
1991	-1.69
1992	-2.741
1993	-3.005
1994	-3.104
1995	-2.187
1996	-1.838
1997	-2.318
1998	-2.42
1999	-1.54
2000	-0.782
2001	1.088
2002	2.526
2003	2.831
2004	3.212