Year	Percent
1983	3.8
1985	8.75
1986	9.9
1987	33.06
1988	15.22
1989	12.16
1990	4.29
1991	9.52
1993	11.24
1995	10.11
1996	10.2
1998	9.91
1999	7.22
2000	5.45
2002	3.45
2005	8.37
2006	5.85
2007	6.74
2008	3.32
2009	1.99
2010	2.9727
2011	1.7003
2012	2.4037
2014	1.2373
2015	1.0788
2016	1.2803