Year	Percent
1999-01-01	85.275
2000-01-01	85.725
2001-01-01	87.000
2002-01-01	86.675
2003-01-01	85.650
2004-01-01	86.350
2005-01-01	86.375
2006-01-01	87.075
2007-01-01	88.125
2008-01-01	88.625
2009-01-01	86.450
2010-01-01	85.200
2011-01-01	84.825
2012-01-01	85.375
2013-01-01	84.350
2014-01-01	84.600
2015-01-01	86.100
2016-01-01	85.625
2017-01-01	88.525