Year	Percent
1999-01-01	65.475
2000-01-01	66.775
2001-01-01	68.325
2002-01-01	67.100
2003-01-01	70.425
2004-01-01	71.250
2005-01-01	68.775
2006-01-01	69.575
2007-01-01	66.925
2008-01-01	66.850
2009-01-01	68.075
2010-01-01	67.800
2011-01-01	68.350
2012-01-01	69.875
2013-01-01	70.175
2014-01-01	72.600
2015-01-01	72.750
2016-01-01	74.925
2017-01-01	75.650