Year	Percent
1990	0.114
1991	0.6
1992	2.004
1993	3.559
1994	4.869
1995	7.824
1996	8.083
1997	6.6498
1998	7.1108
1999	7.9324
2000	12.5465
2001	8.4616
2002	12.7218
2003	8.3391
2004	4.7673
2005	6.6149
2006	6.7745
2007	6.9286
2008	5.2621
2009	11.8922
2010	19.3032
2011	14.757
2012	9.447
2013	8.1624
2014	5.7873
2015	6.8922
2016	9.465
2017	7.4961