Year	Percent
1993	9.6
1995	8
1996	7.7
2004	6.5
2005	5.9
2006	6.8
2007	6.4
2008	6.1
2009	5.9
2010	6.2
2011	6.4
2012	6.5
2013	6.5
2014	6.6
2015	7.1