Year	Percent
2001-01-01	84.575
2002-01-01	84.150
2003-01-01	83.500
2004-01-01	82.950
2005-01-01	83.525
2006-01-01	84.725
2007-01-01	86.075
2008-01-01	86.475
2009-01-01	84.475
2010-01-01	84.025
2011-01-01	85.100
2012-01-01	85.225
2013-01-01	85.400
2014-01-01	85.375
2015-01-01	85.650
2016-01-01	85.950
2017-01-01	86.325