Year	Percent
1999-01-01	53.200
2000-01-01	54.025
2001-01-01	54.475
2002-01-01	56.625
2003-01-01	58.925
2004-01-01	60.725
2005-01-01	63.325
2006-01-01	64.625
2007-01-01	65.375
2008-01-01	67.600
2009-01-01	68.575
2010-01-01	68.925
2011-01-01	69.925
2012-01-01	69.475
2013-01-01	69.225
2014-01-01	69.025
2015-01-01	68.250
2016-01-01	67.600
2017-01-01	66.825