Year	Percent
1983	10.52
1984	8.49
1986	5.56
1988	3.58
1989	3.5
1990	2.54
1991	2.48
1992	1.92
1993	2.61
1994	3.24
1995	2.85
1996	4.641
1997	4.732
1998	5.328
1999	8.761
2000	8.09
2001	7.147
2002	6.386
2003	6.149
2004	6.058
2005	5.507
2006	4.853
2007	4.776
2008	4.723
2009	7.48
2010	4.6013
2011	3.9668
2012	3.5719
2013	3.0745
2014	4.1507
2015	3.3892
2016	3.9801
2017	4.2088