Year	Percent
1990	40.07259
1991	45.25856
1992	49.60046
1993	63.9312
1994	72.49201
1995	82.81698
1996	81.45967
1997	66.06191
1998	57.91103
1999	58.2115
2000	66.44637
2001	59.26502
2002	58.51664
2003	62.89695
2004	58.08608
2005	65.56964
2006	66.7013
2007	68.38427
2008	67.37038
2009	61.45497
2010	56.15397
2011	64.04612
2012	60.9384
2013	53.37838
2014	45.90019
2015	21.88571
2016	40.08054