Year	Years
1970	2.614
1971	3.328
1972	2.754
1973	3.708
1974	3.049
1975	3.78
1976	4.42
1977	4.334
1978	4.255
1979	4.887
1980	5.4
1981	6.15
1982	7.282
1983	6.831
1984	7.668
1985	6.372
1986	4.794
1987	4.395
1988	3.772
1989	2.429
1990	2.391
1991	-0.7566
1992	-1.125
1993	-2.906
1994	-3.872
1995	-2.582
1996	-1.436
1997	-0.8566
1998	0.507
1999	-4.523
2000	-6.96
2001	-5.086
2002	-5.172
2003	-3.861