Year	Percent
2000-01-01	54.350
2001-01-01	55.250
2002-01-01	56.275
2003-01-01	56.575
2004-01-01	56.925
2005-01-01	57.450
2006-01-01	58.075
2007-01-01	59.225
2008-01-01	59.900
2009-01-01	60.425
2010-01-01	58.900
2011-01-01	58.750
2012-01-01	59.300
2013-01-01	59.250
2014-01-01	58.450
2015-01-01	58.775
2016-01-01	58.675
2017-01-01	58.800