Year	Percent
2001-01-01	66.700
2002-01-01	68.025
2003-01-01	68.550
2004-01-01	69.125
2005-01-01	69.525
2006-01-01	69.625
2007-01-01	69.950
2008-01-01	70.075
2009-01-01	69.975
2010-01-01	70.475
2011-01-01	72.025
2012-01-01	72.950
2013-01-01	73.575
2014-01-01	73.975
2015-01-01	74.450
2016-01-01	75.475
2017-01-01	76.425