Year	Percent
1998-01-01	70.950
1999-01-01	70.975
2000-01-01	71.075
2001-01-01	70.800
2002-01-01	69.850
2003-01-01	68.550
2004-01-01	68.125
2005-01-01	67.425
2006-01-01	66.600
2007-01-01	65.500
2008-01-01	64.575
2009-01-01	63.100
2010-01-01	62.125
2011-01-01	60.650
2012-01-01	57.475
2013-01-01	54.750
2014-01-01	51.075
2015-01-01	48.950
2016-01-01	46.600
2017-01-01	44.575