Year	Percent
1999-01-01	61.150
2000-01-01	61.275
2001-01-01	61.475
2002-01-01	61.725
2003-01-01	62.075
2004-01-01	59.775
2005-01-01	60.375
2006-01-01	61.200
2007-01-01	62.300
2008-01-01	63.075
2009-01-01	62.550
2010-01-01	62.850
2011-01-01	63.175
2012-01-01	63.200
2013-01-01	63.100
2014-01-01	62.775
2015-01-01	63.050
2016-01-01	63.575
2017-01-01	64.175