Year	Percent
1999-01-01	63.075
2000-01-01	63.500
2001-01-01	64.075
2002-01-01	63.550
2003-01-01	63.750
2004-01-01	63.725
2005-01-01	63.125
2006-01-01	62.850
2007-01-01	62.575
2008-01-01	63.100
2009-01-01	62.675
2010-01-01	62.850
2011-01-01	62.775
2012-01-01	63.250
2013-01-01	63.350
2014-01-01	63.475
2015-01-01	63.875
2016-01-01	64.425
2017-01-01	64.425