Year	Percent
2000-01-01	78.325
2001-01-01	78.925
2002-01-01	79.075
2003-01-01	79.100
2004-01-01	79.900
2005-01-01	80.925
2006-01-01	81.400
2007-01-01	82.100
2008-01-01	81.950
2009-01-01	81.200
2010-01-01	80.675
2011-01-01	80.450
2012-01-01	80.700
2013-01-01	81.350
2014-01-01	81.725
2015-01-01	81.900
2016-01-01	81.900
2017-01-01	82.800