Year	Percent
1992	75.33167
1993	46.73913
1994	47.117
1995	43.54855
1996	36.00477
1997	37.44269
1998	34.85998
1999	40.11706
2000	49.09727
2001	46.95405
2002	47.04104
2003	43.04631
2004	43.90879
2005	44.56814
2006	40.47823
2007	42.84881
2008	37.14842
2009	33.92765
2010	29.89409
2011	26.65319
2012	29.61407
2013	26.79057
2014	25.63028
2015	24.53302
2016	28.46771