Year	Percent
2001-01-01	86.625
2002-01-01	85.875
2003-01-01	85.275
2004-01-01	84.975
2005-01-01	86.125
2006-01-01	87.750
2007-01-01	89.050
2008-01-01	89.375
2009-01-01	86.875
2010-01-01	87.050
2011-01-01	87.900
2012-01-01	87.850
2013-01-01	87.950
2014-01-01	87.825
2015-01-01	87.925
2016-01-01	88.075
2017-01-01	88.450