Year	Percent
1991	7.4
1995	8.4
1996	8.1
1998	7
1999	7.7
2000	7.8
2001	7.8
2002	7.6
2003	8.1
2004	8.8
2005	8.6
2006	9.3
2007	9.4
2008	8.8
2009	9.2
2010	9.6
2011	10
2012	10.2
2013	9.8
2014	10.2
2015	10.5
2016	10.6