Year	Percent
1999-01-01	53.850
2000-01-01	56.275
2001-01-01	57.825
2002-01-01	58.925
2003-01-01	60.175
2004-01-01	61.325
2005-01-01	63.550
2006-01-01	65.025
2007-01-01	65.800
2008-01-01	64.475
2009-01-01	59.950
2010-01-01	58.850
2011-01-01	58.025
2012-01-01	55.750
2013-01-01	54.825
2014-01-01	56.000
2015-01-01	57.800
2016-01-01	59.550
2017-01-01	61.100