Year	Percent
1998-01-01	60.525
1999-01-01	60.675
2000-01-01	61.100
2001-01-01	61.575
2002-01-01	61.975
2003-01-01	61.950
2004-01-01	61.575
2005-01-01	61.875
2006-01-01	62.050
2007-01-01	62.225
2008-01-01	62.050
2009-01-01	61.350
2010-01-01	61.250
2011-01-01	60.525
2012-01-01	60.175
2013-01-01	59.300
2014-01-01	58.850
2015-01-01	58.575
2016-01-01	58.450
2017-01-01	58.950