Year	Percent
1997	94.1143
1999	83.60051
2000	72.35107
2001	64.53054
2002	57.41449
2003	60.74496
2004	59.3102
2005	48.10912
2006	46.91965
2007	47.52825
2008	45.72979
2009	50.29909
2010	50.66646
2012	53.55289
2013	58.17558
2014	55.59049
2015	55.19602