Year	Percent
1998-01-01	65.425
1999-01-01	65.025
2000-01-01	64.725
2001-01-01	64.075
2002-01-01	64.075
2003-01-01	64.350
2004-01-01	64.350
2005-01-01	64.300
2006-01-01	64.350
2007-01-01	64.150
2008-01-01	64.175
2009-01-01	64.025
2010-01-01	63.575
2011-01-01	62.175
2012-01-01	61.275
2013-01-01	60.900
2014-01-01	60.125
2015-01-01	59.800
2016-01-01	59.825
2017-01-01	59.975