Year	Percent
1999-01-01	69.450
2000-01-01	70.200
2001-01-01	69.825
2002-01-01	70.825
2003-01-01	71.750
2004-01-01	72.175
2005-01-01	73.025
2006-01-01	73.550
2007-01-01	73.900
2008-01-01	74.150
2009-01-01	73.450
2010-01-01	73.175
2011-01-01	72.750
2012-01-01	72.350
2013-01-01	71.675
2014-01-01	70.925
2015-01-01	70.850
2016-01-01	70.475
2017-01-01	70.050