Year	Percent
1995	90.50155
1996	90.24986
1997	90.36775
1998	89.97874
1999	89.96257
2000	89.87242
2001	89.58658
2002	89.22407
2003	89.17903
2004	88.51671
2005	88.59045
2006	88.37601
2007	88.24752
2008	88.18509
2009	88.04609
2010	87.69479
2011	88.27089
2012	88.30918
2013	88.04056
2014	87.96271
2015	88.06089
2016	88.23994
2017	88.33108