Year	Percent
1999-01-01	68.300
2000-01-01	68.200
2001-01-01	68.800
2002-01-01	68.225
2003-01-01	68.275
2004-01-01	68.350
2005-01-01	68.375
2006-01-01	68.250
2007-01-01	67.775
2008-01-01	68.275
2009-01-01	68.125
2010-01-01	67.850
2011-01-01	68.050
2012-01-01	68.350
2013-01-01	68.125
2014-01-01	68.225
2015-01-01	67.875
2016-01-01	68.100
2017-01-01	67.725