Year	Percent
1992	35.57281
1993	38.76808
1994	42.254
1996	50.13002
1997	52.4313
1998	57.49462
1999	62.50481
2000	61.42476
2001	62.4003
2002	63.59851
2003	63.08685
2004	63.25371
2005	65.57785
2006	68.36341
2007	71.46843
2008	74.43691
2009	77.37045
2010	82.58931
2011	88.6131
2012	93.27178
2013	98.0721
2014	100.01418
2015	100.39286
2016	99.38631