Year	Percent
1992	3.756
1993	4.525
1994	6.522
1995	7.556
1996	7.675
1997	9.773
1998	11.052
1999	11.243
2000	8.83
2001	7.272
2002	6.489
2003	6.662
2004	6.21
2005	5.865
2006	5.607
2007	4.811
2008	4.954
2009	6.494
2010	5.83
2011	5.248
2012	4.311
2013	4.3798
2014	4.1814
2015	4.5746
2016	4.7137
2017	4.4271