Year	Percent
2001-01-01	67.150
2002-01-01	67.275
2003-01-01	67.125
2004-01-01	66.900
2005-01-01	67.425
2006-01-01	67.900
2007-01-01	68.350
2008-01-01	68.325
2009-01-01	67.675
2010-01-01	67.100
2011-01-01	67.850
2012-01-01	68.275
2013-01-01	68.650
2014-01-01	69.100
2015-01-01	69.500
2016-01-01	69.650
2017-01-01	70.225