Year	Percent
1992	12.7
1993	9.6
1995	20.3
1996	22.7
2002	11.9
2003	7
2004	5.7
2005	2.6
2006	1.6
2007	1.3
2008	0.4
2009	0.7
2010	0.3
2011	0.2
2012	0.2
2013	0.1
2014	0.1
2015	0.5
2016	0.5