Year	Percent
2000-01-01	70.925
2001-01-01	69.175
2002-01-01	67.400
2003-01-01	67.500
2004-01-01	68.175
2005-01-01	69.550
2006-01-01	71.750
2007-01-01	74.900
2008-01-01	77.450
2009-01-01	77.575
2010-01-01	77.175
2011-01-01	77.275
2012-01-01	77.175
2013-01-01	76.975
2014-01-01	78.400
2015-01-01	79.475
2016-01-01	80.325
2017-01-01	81.375