Year	Percent
1983	19.7569
1984	15.6534
1985	13.2436
1986	9.4582
1987	10.0323
1988	8.9855
1989	12.4049
1990	11.6282
1991	12.3326
1992	12.5536
1993	14.7366
1994	10.2011
1995	12.2802
1996	12.4285
1997	9.9259
1998	7.6229
1999	10.4529
2000	6.9515
2001	9.2654
2002	5.2098
2003	8.9668
2004	7.057
2005	8.58
2006	7.466
2007	7.4021
2008	8.6866
2009	10.295
2010	11.761
2011	12.723
2012	13.4884
2013	11.8103
2014	11.4633
2015	10.0549
2016	10.9034
2017	10.6705