Year	Percent
2005-01-01	80.700
2006-01-01	81.000
2007-01-01	81.600
2008-01-01	81.300
2009-01-01	81.000
2010-01-01	80.125
2011-01-01	80.525
2012-01-01	80.450
2013-01-01	80.050
2014-01-01	80.100
2015-01-01	80.300
2016-01-01	80.575
2017-01-01	80.875