Year	Percent
1978	12.69337
1979	13.82827
1993	27.84039
1994	31.9419
1998	50.76074
1999	53.08246
2000	52.87583
2001	53.91261
2006	71.18581
2008	75.47051
2009	76.77888
2010	80.96895
2011	85.10305
2012	95.50383
2013	92.88871
2014	89.10326
2016	92.28975