Year	Percent
1999-01-01	68.100
2000-01-01	69.450
2001-01-01	68.800
2002-01-01	68.250
2003-01-01	67.250
2004-01-01	67.875
2005-01-01	68.250
2006-01-01	67.925
2007-01-01	68.700
2008-01-01	68.575
2009-01-01	67.150
2010-01-01	67.450
2011-01-01	67.100
2012-01-01	66.900
2013-01-01	66.350
2014-01-01	65.825
2015-01-01	65.500
2016-01-01	66.425
2017-01-01	67.550