Year	Percent
1999-01-01	66.550
2000-01-01	67.175
2001-01-01	68.650
2002-01-01	68.150
2003-01-01	67.375
2004-01-01	69.975
2005-01-01	70.400
2006-01-01	71.125
2007-01-01	72.700
2008-01-01	72.700
2009-01-01	71.025
2010-01-01	69.650
2011-01-01	67.700
2012-01-01	67.425
2013-01-01	67.075
2014-01-01	67.550
2015-01-01	69.200
2016-01-01	68.875
2017-01-01	72.525