Year	Percent
1999-01-01	90.600
2000-01-01	90.600
2001-01-01	91.100
2002-01-01	91.225
2003-01-01	90.575
2004-01-01	90.950
2005-01-01	91.100
2006-01-01	91.050
2007-01-01	91.275
2008-01-01	91.600
2009-01-01	91.225
2010-01-01	91.750
2011-01-01	91.850
2012-01-01	92.350
2013-01-01	92.600
2014-01-01	92.250
2015-01-01	92.875
2016-01-01	91.975
2017-01-01	93.350