Year	Percent
1983	8.10572
1984	14.3717
1985	3.14455
1986	5.63706
1987	11.8784
1988	8.84258
1989	12.49382
1990	10.98994
1991	11.63705
1992	14.83111
1993	9.55126
1994	6.74031
1995	8.19336
1996	2.21821
1997	1.64271
1998	-1.98013
1999	-1.24737
2000	-1.66854
2001	-1.40181
2002	-1.3212
2003	0.08037
2004	1.9185
2005	5.56634
2006	7.80543
2007	8.82116
2008	10.09063
2009	0.87712
2010	4.77911
2011	7.49431
2012	6.92975
2013	7.72605
2014	8.63859
2015	4.50245
2016	0.88511
2017	2.27268