Year	Percent
1995	34.56705
1996	40.45055
1997	39.71451
1998	39.18882
1999	35.03117
2000	36.88261
2001	38.05599
2002	36.5801
2003	36.11873
2004	39.08135
2005	43.17541
2006	39.97328
2007	38.45099
2008	39.54232
2009	42.60288
2010	53.65732
2011	57.81669
2012	61.30948
2013	60.30418
2014	60.74088
2015	60.4038
2016	60.04199
2017	60.46669