Year	Percent
1998-01-01	56.000
1999-01-01	57.075
2000-01-01	57.925
2001-01-01	59.325
2002-01-01	60.350
2003-01-01	60.925
2004-01-01	63.875
2005-01-01	63.700
2006-01-01	64.375
2007-01-01	64.125
2008-01-01	65.275
2009-01-01	64.575
2010-01-01	64.500
2011-01-01	64.675
2012-01-01	66.475
2013-01-01	66.100
2014-01-01	66.375
2015-01-01	65.875
2016-01-01	66.775
2017-01-01	67.300