Year	Percent
1999-01-01	56.225
2000-01-01	56.875
2001-01-01	57.725
2002-01-01	57.250
2003-01-01	56.300
2004-01-01	58.875
2005-01-01	59.375
2006-01-01	59.925
2007-01-01	61.075
2008-01-01	61.475
2009-01-01	60.550
2010-01-01	59.650
2011-01-01	57.925
2012-01-01	57.375
2013-01-01	56.525
2014-01-01	57.225
2015-01-01	57.600
2016-01-01	57.750
2017-01-01	60.575