Year	Percent
1976	5.46657
1977	5.8286
1978	8.5054
1979	9.35763
1988	19.12873
1993	24.1138
1994	28.55048
1998	45.79889
1999	48.99689
2000	49.50094
2001	50.43721
2004	60.35946
2005	66.43449
2006	71.36739
2007	72.78609
2008	78.40036
2009	80.54729
2010	86.73383
2011	88.09697
2012	97.69799
2013	95.20152
2014	94.74519
2016	97.41589