Year	Percent
1998-01-01	60.475
1999-01-01	62.500
2000-01-01	63.275
2001-01-01	63.650
2002-01-01	64.050
2003-01-01	63.475
2004-01-01	63.325
2005-01-01	64.150
2006-01-01	64.650
2007-01-01	65.075
2008-01-01	65.150
2009-01-01	64.725
2010-01-01	63.725
2011-01-01	63.525
2012-01-01	63.800
2013-01-01	63.400
2014-01-01	63.475
2015-01-01	63.750
2016-01-01	63.150
2017-01-01	63.500