Year	Percent
1990	0.01939
1991	0.5108
1992	0.40095
1993	0.36935
1994	1.08689
1995	0.69201
1996	1.07818
1997	4.50891
1998	3.67246
1999	6.06731
2000	7.61425
2001	5.77554
2002	5.55809
2003	9.99295
2004	11.83664
2005	13.8279
2006	23.07192
2007	31.24253
2008	18.92462
2009	7.51027
2010	3.64137
2011	3.664
2012	3.31727
2013	3.56722
2014	3.6444
2015	5.39191
2016	3.10955
2017	2.9143