Year	Percent
2000-01-01	81.300
2001-01-01	80.700
2002-01-01	79.900
2003-01-01	78.325
2004-01-01	77.925
2005-01-01	77.850
2006-01-01	78.425
2007-01-01	79.525
2008-01-01	80.475
2009-01-01	78.325
2010-01-01	77.250
2011-01-01	77.125
2012-01-01	77.650
2013-01-01	77.275
2014-01-01	77.000
2015-01-01	76.525
2016-01-01	75.700
2017-01-01	75.575