Year	Percent
1989	10.2
1990	10.9
1991	12.3
1992	12.2
1993	11.8
1994	11.4
1995	11.3
1996	11.4
1997	12.2
1998	11.5
1999	11.9
2001	11.6
2002	11.5
2003	10.7
2004	10.7
2005	10.6
2006	11.3
2007	11.2
2008	11.7
2009	12.8
2010	12
2011	11.4
2012	11.4
2013	12.3
2014	12.9
2015	13.2
2016	13.3