Year	Percent
1998-01-01	59.000
1999-01-01	59.575
2000-01-01	60.125
2001-01-01	60.600
2002-01-01	61.075
2003-01-01	61.500
2004-01-01	62.800
2005-01-01	62.475
2006-01-01	62.650
2007-01-01	62.400
2008-01-01	62.900
2009-01-01	62.275
2010-01-01	62.025
2011-01-01	62.050
2012-01-01	63.475
2013-01-01	63.350
2014-01-01	63.950
2015-01-01	64.050
2016-01-01	64.950
2017-01-01	65.450