Year	Percent
2000-01-01	80.225
2001-01-01	80.375
2002-01-01	80.450
2003-01-01	80.600
2004-01-01	80.875
2005-01-01	81.250
2006-01-01	81.175
2007-01-01	81.300
2008-01-01	81.300
2009-01-01	80.100
2010-01-01	79.750
2011-01-01	80.025
2012-01-01	80.450
2013-01-01	80.850
2014-01-01	82.075
2015-01-01	82.375
2016-01-01	82.950
2017-01-01	83.775