Year	Percent
2003-01-01	77.300
2004-01-01	75.700
2005-01-01	77.100
2006-01-01	77.750
2007-01-01	77.750
2008-01-01	76.975
2009-01-01	76.400
2010-01-01	76.800
2011-01-01	76.400
2012-01-01	77.100
2013-01-01	77.650
2014-01-01	78.650
2015-01-01	79.650
2016-01-01	79.775
2017-01-01	78.875