Quarter	Percent
1998-04-01	83.9
1998-10-01	82.0
1999-04-01	82.1
1999-10-01	82.3
2000-04-01	82.7
2000-10-01	83.8
2001-04-01	83.6
2001-10-01	82.3
2002-01-01	79.9
2002-04-01	83.2
2002-07-01	80.6
2002-10-01	84.2
2003-01-01	82.4
2003-04-01	83.2
2003-07-01	84.0
2003-10-01	81.4
2004-01-01	82.8
2004-04-01	81.4
2004-07-01	83.5
2004-10-01	82.7
2005-01-01	81.8
2005-04-01	81.8
2005-07-01	80.5
2005-10-01	82.0
2006-01-01	80.9
2006-04-01	83.3
2006-07-01	81.9
2006-10-01	82.8
2007-01-01	80.7
2007-04-01	81.4
2007-07-01	83.9
2007-10-01	85.0
2008-01-01	84.6
2008-04-01	85.2
2008-07-01	85.6
2008-10-01	86.9
2009-01-01	87.2
2009-04-01	85.5
2009-07-01	84.5
2009-10-01	86.3
2010-01-01	85.2
2010-04-01	86.2
2010-07-01	86.6
2010-10-01	87.3
2011-01-01	85.2
2011-04-01	85.4
2011-07-01	86.4
2011-10-01	84.4
2012-01-01	85.0
2012-04-01	85.7
2012-07-01	86.5
2012-10-01	85.8
2013-01-01	85.5
2013-04-01	84.8
2013-07-01	85.5
2013-10-01	83.4
2014-01-01	85.0
2014-04-01	84.8
2014-07-01	83.9
2014-10-01	82.3
2015-01-01	83.0
2015-04-01	84.6
2015-07-01	86.1
2015-10-01	84.7
2016-01-01	85.3
2016-04-01	84.7
2016-07-01	86.3
2016-10-01	85.8
2017-01-01	85.0
2017-04-01	83.7
2017-07-01	86.3
2017-10-01	86.7
2018-01-01	86.1
2018-04-01	85.7