Year	Percent
1999-01-01	66.275
2000-01-01	66.325
2001-01-01	67.075
2002-01-01	66.400
2003-01-01	65.900
2004-01-01	68.425
2005-01-01	68.900
2006-01-01	68.800
2007-01-01	69.500
2008-01-01	69.050
2009-01-01	68.925
2010-01-01	69.125
2011-01-01	67.600
2012-01-01	67.050
2013-01-01	67.325
2014-01-01	67.625
2015-01-01	67.600
2016-01-01	66.225
2017-01-01	68.225