Year	Percent
2001-01-01	72.275
2002-01-01	72.225
2003-01-01	71.450
2004-01-01	70.500
2005-01-01	70.225
2006-01-01	70.700
2007-01-01	71.750
2008-01-01	71.850
2009-01-01	70.200
2010-01-01	69.650
2011-01-01	71.275
2012-01-01	71.825
2013-01-01	72.475
2014-01-01	73.125
2015-01-01	73.975
2016-01-01	74.825
2017-01-01	75.400