Year	Percent
1998-01-01	62.000
1999-01-01	61.950
2000-01-01	61.950
2001-01-01	61.750
2002-01-01	61.925
2003-01-01	62.150
2004-01-01	61.600
2005-01-01	61.075
2006-01-01	60.825
2007-01-01	60.450
2008-01-01	60.400
2009-01-01	59.600
2010-01-01	59.075
2011-01-01	58.725
2012-01-01	59.250
2013-01-01	58.650
2014-01-01	58.700
2015-01-01	58.875
2016-01-01	59.250
2017-01-01	59.350