Year	Percent
2000-01-01	80.175
2001-01-01	80.025
2002-01-01	79.850
2003-01-01	78.700
2004-01-01	78.450
2005-01-01	78.325
2006-01-01	78.025
2007-01-01	78.775
2008-01-01	80.050
2009-01-01	78.875
2010-01-01	78.125
2011-01-01	77.825
2012-01-01	78.275
2013-01-01	78.175
2014-01-01	78.000
2015-01-01	78.225
2016-01-01	78.050
2017-01-01	77.325