Quarter	Percent
1998-04-01	87.2
1999-04-01	87.2
2000-04-01	87.3
2001-04-01	87.6
2002-04-01	86.2
2003-04-01	85.1
2004-04-01	84.4
2005-04-01	83.9
2006-04-01	84.7
2007-04-01	85.6
2008-04-01	85.4
2009-04-01	84.4
2010-01-01	82.1
2010-04-01	83.4
2010-07-01	83.9
2010-10-01	83.5
2011-01-01	83.5
2011-04-01	84.0
2011-07-01	84.5
2011-10-01	84.2
2012-01-01	83.2
2012-04-01	83.9
2012-07-01	84.5
2012-10-01	84.0
2013-01-01	83.0
2013-04-01	83.3
2013-07-01	83.5
2013-10-01	84.0
2014-01-01	82.4
2014-04-01	83.2
2014-07-01	83.5
2014-10-01	84.3
2015-01-01	83.3
2015-04-01	83.6
2015-07-01	83.3
2015-10-01	84.1
2016-01-01	83.0
2016-04-01	83.5
2016-07-01	83.8
2016-10-01	84.5
2017-01-01	83.1
2017-04-01	84.6
2017-07-01	84.7
2017-10-01	84.7
2018-01-01	83.5
2018-04-01	84.7