Year	Percent
1999-01-01	72.325
2000-01-01	70.725
2001-01-01	68.025
2002-01-01	68.575
2003-01-01	65.625
2004-01-01	67.875
2005-01-01	68.125
2006-01-01	69.950
2007-01-01	70.625
2008-01-01	72.150
2009-01-01	70.900
2010-01-01	67.525
2011-01-01	67.075
2012-01-01	64.050
2013-01-01	61.725
2014-01-01	61.500
2015-01-01	62.100
2016-01-01	66.125
2017-01-01	63.250