Year	Percent
1986	17.11
1987	16.45
1988	18.16
1989	15.98
1992	21.41
1995	18.8
1997	15.51
2003	10.11
2009	8.53
2010	9.48
2013	10.12
2014	11
2015	9.55
2016	8.81