Year	Percent
1992	0.67812
1993	1.22256
1994	1.74596
1995	2.05937
1996	2.14711
1997	1.99158
1998	1.48918
1999	1.47272
2000	1.15125
2001	1.14296
2002	1.26565
2003	1.83005
2004	2.11091
2005	2.61719
2006	2.69547
2007	2.69243
2008	2.49159
2009	3.07638
2010	3.8903
2011	4.19897
2012	5.34092
2013	5.94837
2014	5.12275
2015	4.36748
2016	3.77763
2017	2.92164