Year	Percent
1999-01-01	73.425
2000-01-01	73.750
2001-01-01	73.175
2002-01-01	73.175
2003-01-01	72.875
2004-01-01	73.400
2005-01-01	73.900
2006-01-01	73.400
2007-01-01	73.650
2008-01-01	73.325
2009-01-01	72.825
2010-01-01	73.450
2011-01-01	72.300
2012-01-01	72.475
2013-01-01	72.725
2014-01-01	72.450
2015-01-01	72.175
2016-01-01	72.350
2017-01-01	72.750