Year	Percent
1998-01-01	70.650
1999-01-01	70.500
2000-01-01	71.275
2001-01-01	71.800
2002-01-01	71.275
2003-01-01	69.875
2004-01-01	69.025
2005-01-01	68.250
2006-01-01	68.650
2007-01-01	68.575
2008-01-01	68.525
2009-01-01	65.775
2010-01-01	64.650
2011-01-01	62.900
2012-01-01	59.975
2013-01-01	58.775
2014-01-01	60.275
2015-01-01	61.000
2016-01-01	62.100
2017-01-01	64.400