Year	Percent
1998-01-01	67.225
1999-01-01	69.125
2000-01-01	70.075
2001-01-01	70.825
2002-01-01	69.975
2003-01-01	69.675
2004-01-01	69.700
2005-01-01	70.275
2006-01-01	71.375
2007-01-01	72.125
2008-01-01	73.125
2009-01-01	69.500
2010-01-01	69.375
2011-01-01	70.575
2012-01-01	70.550
2013-01-01	69.925
2014-01-01	69.475
2015-01-01	69.325
2016-01-01	70.500
2017-01-01	71.375