Year	Percent
1976	72.64691
1977	78.77998
1978	73.58757
1979	77.27933
1985	83.53326
1987	80.23311
1988	78.71397
1989	82.20015
2005	66.60202
2006	73.34743
2007	65.51461
2008	74.6436
2009	78.41986
2010	81.7872
2011	80.89717
2012	81.76774
2013	80.38121
2014	83.48837
2015	86.05694
2016	83.60752