Year	Percent
1999-01-01	86.325
2000-01-01	87.350
2001-01-01	86.525
2002-01-01	86.075
2003-01-01	84.975
2004-01-01	85.800
2005-01-01	86.125
2006-01-01	85.875
2007-01-01	86.975
2008-01-01	87.050
2009-01-01	85.700
2010-01-01	85.525
2011-01-01	84.850
2012-01-01	84.500
2013-01-01	84.025
2014-01-01	83.225
2015-01-01	82.550
2016-01-01	83.750
2017-01-01	84.375