Year	Percent
1996	84.77152
1997	84.99571
1998	86.11
1999	86.5624
2000	86.78676
2001	87.1692
2002	87.97306
2003	87.85805
2004	86.79864
2005	87.45334
2006	88.45365
2007	88.51584
2008	88.70701
2009	88.46323
2010	88.70666
2011	88.79602
2012	89.36853
2013	89.83153
2014	89.75192
2015	90.0611
2016	90.3287
2017	90.77969