Year	Percent
2000-01-01	88.325
2001-01-01	87.675
2002-01-01	87.225
2003-01-01	87.100
2004-01-01	87.775
2005-01-01	88.750
2006-01-01	88.150
2007-01-01	87.925
2008-01-01	88.800
2009-01-01	89.375
2010-01-01	89.650
2011-01-01	89.725
2012-01-01	90.050
2013-01-01	90.050
2014-01-01	90.475
2015-01-01	90.575
2016-01-01	90.750
2017-01-01	91.075