Year	Percent
1992	5.167
1993	5.822
1994	7.95
1995	9.196
1996	9.296
1997	11.454
1998	12.953
1999	12.896
2000	10.367
2001	8.597
2002	7.599
2003	7.952
2004	7.518
2005	6.935
2006	6.687
2007	5.642
2008	5.944
2009	7.672
2010	6.8361
2011	6.0867
2012	5.0696
2013	5.1361
2014	4.8219
2015	5.3092
2016	5.3477
2017	5.0514