Year	Percent
1999-01-01	62.600
2000-01-01	64.150
2001-01-01	65.475
2002-01-01	64.525
2003-01-01	67.275
2004-01-01	67.325
2005-01-01	65.550
2006-01-01	67.075
2007-01-01	64.950
2008-01-01	65.225
2009-01-01	64.850
2010-01-01	63.275
2011-01-01	63.825
2012-01-01	65.925
2013-01-01	66.500
2014-01-01	68.900
2015-01-01	69.825
2016-01-01	71.950
2017-01-01	72.750