Year	Percent
1994	2.911
1995	3.5972
1996	5.1145
1997	4.5463
1998	4.9199
1999	4.4779
2000	4.1916
2001	3.4007
2002	4.5715
2003	4.4608
2004	4.7442
2005	4.4812
2006	4.1284
2007	3.8447
2008	3.3997
2009	4.9325
2010	4.5685
2011	3.8916
2012	4.3515
2013	4.9834
2014	5.3589
2015	5.4522
2016	5.7034
2017	5.4987