Year	Percent
1999-01-01	84.075
2000-01-01	84.025
2001-01-01	84.400
2002-01-01	83.650
2003-01-01	83.750
2004-01-01	84.725
2005-01-01	84.450
2006-01-01	85.450
2007-01-01	85.350
2008-01-01	86.375
2009-01-01	86.475
2010-01-01	85.250
2011-01-01	84.725
2012-01-01	84.850
2013-01-01	84.825
2014-01-01	83.775
2015-01-01	83.400
2016-01-01	83.825
2017-01-01	82.675