Year	Percent
1993	4.2
1995	3.2
1996	2.9
2004	2.2
2005	2
2006	2.4
2007	2.4
2008	2.1
2009	2
2010	2.1
2011	2.3
2012	2.3
2013	2.3
2014	2.3
2015	2.5