Year	Percent
1998-01-01	87.000
1999-01-01	87.725
2000-01-01	87.875
2001-01-01	87.975
2002-01-01	88.000
2003-01-01	87.450
2004-01-01	87.400
2005-01-01	87.700
2006-01-01	87.825
2007-01-01	88.025
2008-01-01	88.600
2009-01-01	88.250
2010-01-01	87.500
2011-01-01	87.650
2012-01-01	87.300
2013-01-01	86.750
2014-01-01	86.625
2015-01-01	86.625
2016-01-01	86.275
2017-01-01	86.775