Year	Percent
2000-01-01	84.150
2001-01-01	83.675
2002-01-01	83.175
2003-01-01	81.925
2004-01-01	81.725
2005-01-01	81.625
2006-01-01	81.250
2007-01-01	81.625
2008-01-01	82.750
2009-01-01	81.275
2010-01-01	80.600
2011-01-01	79.900
2012-01-01	80.575
2013-01-01	80.250
2014-01-01	80.075
2015-01-01	80.300
2016-01-01	80.125
2017-01-01	79.325