Year	Percent
2001	83.73911
2002	83.90789
2003	83.67289
2004	82.51502
2005	83.96288
2006	83.62205
2007	82.54512
2008	83.50646
2009	82.67284
2010	82.77905
2011	83.74339
2012	82.12996
2013	79.52462
2014	78.98578
2015	76.00485
2016	75.79858
