Quarter	Percent
1998-04-01	78.5
1999-04-01	77.7
2000-04-01	78
2001-04-01	79.5
2002-04-01	80.6
2003-04-01	80.5
2004-04-01	80.8
2005-04-01	81.3
2006-04-01	81.2
2007-04-01	81.9
2008-04-01	83.6
2009-04-01	83.9
2010-01-01	81.6
2010-04-01	82.0
2010-07-01	82.0
2010-10-01	82.2
2011-01-01	82.8
2011-04-01	82.6
2011-07-01	82.4
2011-10-01	83.6
2012-01-01	83.3
2012-04-01	83.5
2012-07-01	83.7
2012-10-01	83.9
2013-01-01	83.6
2013-04-01	83.5
2013-07-01	83.4
2013-10-01	83.7
2014-01-01	84.2
2014-04-01	84.5
2014-07-01	84.6
2014-10-01	85.7
2015-01-01	85.0
2015-04-01	85.0
2015-07-01	84.4
2015-10-01	84.9
2016-01-01	86.5
2016-04-01	85.0
2016-07-01	84.8
2016-10-01	85.8
2017-01-01	86.0
2017-04-01	85.2
2017-07-01	85.3
2017-10-01	85.7
2018-01-01	86.1
2018-04-01	86.1