Year	Percent
1991	55.25599
1992	38.62547
1993	30.6428
1994	37.23403
1995	27.97831
1996	17.96235
1997	13.66176
1998	11.02727
1999	6.16253
2000	6.11461
2001	3.12287
2002	1.84923
2003	0.76653
2004	4.91222
2005	2.56902
2006	1.72572
2007	3.71335
2008	3.87652
2009	3.77123
2010	1.65966
2011	3.22912
2012	2.34972
2013	0.28994
2014	0.49528
2015	0.7562
2016	0.41625
2017	2.01043