Year	Percent
1990	0.405
1991	1.205
1992	3.496
1993	6.398
1994	6.913
1995	10.481
1996	10.055
1997	10.5115
1998	10.1454
1999	12.4
2000	14.5638
2001	13.0931
2002	10.2827
2003	10.8851
2004	10.1975
2005	8.6487
2006	5.7224
2007	4.1612
2008	4.8933
2009	15.7618
2010	17.392
2011	11.4415
2012	9.7812
2013	8.3179
2014	7.1295
2015	5.3127
2016	6.1838
2017	5.175