Year	Percent
2001	82.29339
2002	83.24362
2003	82.44637
2004	81.11037
2005	81.73061
2006	80.98588
2007	80.5176
2008	80.43154
2009	80.39083
2010	80.35753
2011	82.07469
2012	81.17992
2013	80.23162
2014	79.99737
2015	77.85899
2016	77.75255