Year	Percent
1999-01-01	71.925
2000-01-01	71.200
2001-01-01	71.575
2002-01-01	71.150
2003-01-01	71.375
2004-01-01	71.600
2005-01-01	71.075
2006-01-01	71.100
2007-01-01	70.975
2008-01-01	71.200
2009-01-01	70.200
2010-01-01	69.075
2011-01-01	68.375
2012-01-01	67.375
2013-01-01	66.250
2014-01-01	66.450
2015-01-01	66.750
2016-01-01	67.775
2017-01-01	66.400