Quarter	Percent
1998-04-01	67.4
1999-04-01	69
2000-04-01	68.4
2001-04-01	67.8
2002-04-01	69.3
2003-04-01	69.4
2004-04-01	67.1
2005-04-01	65.7
2006-04-01	68.6
2007-04-01	67.4
2008-04-01	67.1
2009-04-01	67.3
2010-01-01	68.0
2010-04-01	66.5
2010-07-01	70.5
2010-10-01	67.4
2011-01-01	68.0
2011-04-01	66.8
2011-07-01	70.2
2011-10-01	69.2
2012-01-01	67.2
2012-04-01	65.2
2012-07-01	70.0
2012-10-01	67.9
2013-01-01	68.4
2013-04-01	66.2
2013-07-01	68.5
2013-10-01	69.0
2014-01-01	67.2
2014-04-01	66.4
2014-07-01	68.8
2014-10-01	69.2
2015-01-01	66.4
2015-04-01	65.6
2015-07-01	68.6
2015-10-01	69.4
2016-01-01	68.3
2016-04-01	65.8
2016-07-01	69.1
2016-10-01	70.1
2017-01-01	68.4
2017-04-01	66.6
2017-07-01	70.9
2017-10-01	68.8
2018-01-01	66.8
2018-04-01	65.6