Year	Percent
1998	88.65417
1999	90.31697
2000	92.50517
2001	90.8399
2002	91.17056
2003	89.78519
2004	90.89655
2005	90.72845
2006	89.65912
2007	89.62673
2008	89.71453
2009	90.61838
2010	92.28973
2011	92.62822
2012	92.05823
2013	90.69512
2014	91.00801
2015	90.43536
2016	88.78844
2017	89.12985