Year	Percent
1993	0.64401
1994	4.27934
1995	3.44242
1996	2.3032
1997	2.42984
1998	2.82778
1999	4.20106
2000	5.50896
2001	4.30329
2002	4.37443
2003	3.88347
2004	2.53944
2005	3.95663
2006	3.44952
2007	4.05115
2008	3.79062
2009	6.77556
2010	5.90488
2011	6.88613
2012	9.52337
2013	10.39397
2014	12.11051
2015	16.00483
2016	19.4171