Year	Percent
1986	8.6
1989	7.9
1992	8.1
1996	8.8
1997	8.5
2000	7.6
2001	8
2002	8.2
2003	7.8
2004	7.8
2005	8.1
2006	7.7
2007	8.5
2008	8.6
2009	8.5
2010	8.6
2011	8.7
2012	9.2
2013	8.9
2014	9.4
2015	9.4
2016	9.1