Year	Percent
1999-01-01	56.300
2000-01-01	57.575
2001-01-01	56.900
2002-01-01	58.825
2003-01-01	60.250
2004-01-01	61.250
2005-01-01	62.425
2006-01-01	63.575
2007-01-01	64.450
2008-01-01	65.400
2009-01-01	65.700
2010-01-01	66.050
2011-01-01	66.275
2012-01-01	66.500
2013-01-01	66.150
2014-01-01	65.600
2015-01-01	65.550
2016-01-01	65.350
2017-01-01	64.900