Year	Percent
1992	0.47139
1993	0.54655
1994	0.89148
1995	0.812
1996	1.72431
1997	1.95261
1998	2.26799
1999	0.61689
2000	2.73584
2001	0.87857
2002	2.95357
2003	2.0365
2004	13.10239
2005	2.35605
2006	11.96463
2007	9.67785
2008	7.28082
2009	0.31769
2010	1.40747
2011	2.47013
2012	3.13567
2013	1.47511
2014	3.34882
2015	5.42625
2016	3.46007
2017	2.80037