Year	Percent
1993	5.443
1994	5.193
1995	4.807
1996	4.662
1997	5.121
1998	7.5493
1999	10.1211
2000	10.5279
2001	9.6052
2002	8.553
2003	9.6389
2004	9.6509
2005	9.7928
2006	8.8453
2007	6.7379
2008	5.6122
2009	7.7299
2010	8.4553
2011	7.8937
2012	8.2054
2013	8.287
2014	7.394
2015	6.0743
2016	4.6706
2017	3.5799
