Year	Percent
1999-01-01	68.525
2000-01-01	68.500
2001-01-01	68.375
2002-01-01	68.750
2003-01-01	68.950
2004-01-01	66.525
2005-01-01	67.400
2006-01-01	68.575
2007-01-01	69.875
2008-01-01	70.825
2009-01-01	70.325
2010-01-01	70.775
2011-01-01	71.100
2012-01-01	71.425
2013-01-01	71.400
2014-01-01	71.075
2015-01-01	71.100
2016-01-01	71.550
2017-01-01	72.200