Year	Percent
1990	7.8
1991	8.678
1992	8.816
1993	8.825
1994	8.775
1995	7.773
1996	6.896
1997	6.474
1998	6.919
1999	7.728
2000	6.577
2001	8.724
2002	10.716
2003	10.711
2004	10.785
2005	10.447
2006	8.5854
2007	8.7705
2008	9.6119
2009	12.5305
2010	10.3668
2011	8.2665
2012	7.627
2013	7.9309
2014	9.0295
2015	9.1768
2016	9.5511
2017	9.3676