Year	Percent
1999-01-01	62.325
2000-01-01	63.175
2001-01-01	63.675
2002-01-01	63.175
2003-01-01	63.475
2004-01-01	62.950
2005-01-01	61.500
2006-01-01	60.925
2007-01-01	60.750
2008-01-01	61.350
2009-01-01	60.600
2010-01-01	61.300
2011-01-01	60.850
2012-01-01	61.675
2013-01-01	62.450
2014-01-01	62.875
2015-01-01	64.275
2016-01-01	65.375
2017-01-01	65.875