Year	Percent
1998-01-01	62.650
1999-01-01	62.500
2000-01-01	63.825
2001-01-01	66.125
2002-01-01	66.825
2003-01-01	68.800
2004-01-01	66.575
2005-01-01	69.550
2006-01-01	71.400
2007-01-01	72.500
2008-01-01	73.925
2009-01-01	72.600
2010-01-01	72.950
2011-01-01	73.425
2012-01-01	72.975
2013-01-01	74.725
2014-01-01	73.925
2015-01-01	75.700
2016-01-01	77.125
2017-01-01	76.075