Year	Percent
1996	90.82659
1997	90.83761
1998	90.54807
1999	90.33832
2000	91.592
2001	90.89465
2002	91.25794
2003	92.57225
2004	91.79883
2005	92.10838
2006	91.34915
2007	91.68069
2008	92.49653
2009	90.99913
2010	89.64201
2011	89.82125
2012	90.21486
2013	89.75007
2014	88.99438
2015	88.75745
2016	89.41423
2017	89.41108