Year	Percent
1990	6.26
1991	6.62
1992	7.02
1994	6.09
1995	6.46
1996	10.48
1997	10.84
1998	10.65
1999	14.33
2001	11.35
2002	11.02
2003	10.06
2004	9.13
2005	9.06
2006	7.78
2007	8.35
2008	7.7
2009	9.25
2010	10.59
2011	10.84
2012	9.43
2013	10.41
2014	10.14
2015	11.26
2016	10.49
2017	11