Year	Percent
2000-01-01	50.200
2001-01-01	51.050
2002-01-01	54.625
2003-01-01	56.725
2004-01-01	56.875
2005-01-01	56.950
2006-01-01	57.950
2007-01-01	61.550
2008-01-01	63.650
2009-01-01	65.400
2010-01-01	64.500
2011-01-01	64.475
2012-01-01	66.900
2013-01-01	68.875
2014-01-01	69.375
2015-01-01	71.100
2016-01-01	72.800
2017-01-01	74.750