Year	Percent
1996	6.97
1998	8.31
1999	10.29
2000	10.87
2001	14.39
2002	12.24
2003	11.44
2004	8.53
2005	10.42
2006	10.9
2007	10.11
2008	10.28
2009	10.22
2010	10.05
2011	9.57
2012	8.51
2013	8.97
2014	8.8
2015	7.94
2016	6.52
2017	6.34