Year	Percent
1996	87.5622
1997	87.92385
1998	87.28893
1999	87.02822
2000	88.43898
2001	87.71556
2002	87.72608
2003	89.72111
2004	89.15555
2005	89.53896
2006	88.55208
2007	88.80448
2008	89.73898
2009	87.67162
2010	86.5857
2011	86.92188
2012	87.17846
2013	86.72018
2014	86.42386
2015	85.72372
2016	86.62316
2017	87.14398