Year	Percent
2001-01-01	75.725
2002-01-01	75.750
2003-01-01	75.400
2004-01-01	75.150
2005-01-01	75.850
2006-01-01	76.275
2007-01-01	76.775
2008-01-01	76.925
2009-01-01	76.400
2010-01-01	76.225
2011-01-01	77.350
2012-01-01	77.925
2013-01-01	78.750
2014-01-01	79.300
2015-01-01	79.900
2016-01-01	80.175
2017-01-01	80.650