Year	Percent
1992	5.194
1993	5.937
1994	8.293
1995	9.675
1996	9.996
1997	12.137
1998	13.539
1999	13.167
2000	10.78
2001	9.335
2002	8.139
2003	8.458
2004	8.001
2005	7.308
2006	7.415
2007	6.352
2008	6.456
2009	8.909
2010	7.8777
2011	6.9651
2012	5.7863
2013	5.7635
2014	5.4807
2015	5.8175
2016	5.7577
2017	5.3638