Year	Percent
1999-01-01	83.425
2000-01-01	84.200
2001-01-01	84.675
2002-01-01	84.900
2003-01-01	84.350
2004-01-01	86.175
2005-01-01	86.425
2006-01-01	86.975
2007-01-01	87.300
2008-01-01	88.525
2009-01-01	87.925
2010-01-01	88.100
2011-01-01	88.375
2012-01-01	89.075
2013-01-01	88.675
2014-01-01	88.275
2015-01-01	88.575
2016-01-01	88.900
2017-01-01	90.275