Year	Percent
2001-01-01	87.975
2002-01-01	87.700
2003-01-01	87.700
2004-01-01	87.675
2005-01-01	88.825
2006-01-01	89.425
2007-01-01	90.025
2008-01-01	90.400
2009-01-01	90.050
2010-01-01	89.825
2011-01-01	90.275
2012-01-01	90.575
2013-01-01	90.875
2014-01-01	90.800
2015-01-01	90.900
2016-01-01	90.950
2017-01-01	91.250