Quarter	Percent
1999-04-01	87.8
2000-04-01	86.2
2001-04-01	86.6
2002-04-01	88.4
2003-01-01	85.6
2003-04-01	84.7
2003-07-01	84.6
2003-10-01	84.4
2004-01-01	84.8
2004-04-01	82.7
2004-07-01	82.3
2004-10-01	86.5
2005-01-01	84.1
2005-04-01	85
2005-07-01	84.7
2005-10-01	88.3
2006-01-01	87.1
2006-04-01	86
2006-07-01	84.1
2006-10-01	85.1
2007-01-01	87.1
2007-04-01	85.3
2007-07-01	84.1
2007-10-01	85.2
2008-01-01	83.6
2008-04-01	86.6
2008-07-01	83.3
2008-10-01	83.5
2009-01-01	83
2009-04-01	81.6
2009-07-01	83.3
2009-10-01	85.2
2010-01-01	84.1
2010-04-01	82.4
2010-07-01	83.3
2010-10-01	84.2
2011-01-01	83.7
2011-04-01	82
2011-07-01	84.1
2011-10-01	85.3
2012-01-01	81.3
2012-04-01	82.2
2012-07-01	83.1
2012-10-01	83.8
2013-01-01	83
2013-04-01	84.3
2013-07-01	83.5
2013-10-01	84.6
2014-01-01	86.1
2014-04-01	88.2
2014-07-01	87.6
2014-10-01	87.8
2015-01-01	88.0
2015-04-01	86.6
2015-07-01	89.1
2015-10-01	86.5
2016-01-01	87.4
2016-04-01	86.4
2016-07-01	86.7
2016-10-01	85.0
2017-01-01	86.8
2017-04-01	85.9
2017-07-01	84.1
2017-10-01	84.8
2018-01-01	81.6
2018-04-01	81.2