Quarter	Percent
1999-04-01	83.5
2000-04-01	85.9
2001-04-01	84.8
2002-04-01	84.1
2003-01-01	81.4
2003-04-01	84.3
2003-07-01	84.8
2003-10-01	80.5
2004-01-01	80.4
2004-04-01	82.3
2004-07-01	82.1
2004-10-01	80
2005-01-01	81.8
2005-04-01	84.3
2005-07-01	82.2
2005-10-01	82.3
2006-01-01	82.1
2006-04-01	85.4
2006-07-01	84.3
2006-10-01	81.7
2007-01-01	82.5
2007-04-01	84.8
2007-07-01	83.3
2007-10-01	80.3
2008-01-01	80.1
2008-04-01	83.4
2008-07-01	82.3
2008-10-01	81
2009-01-01	79.5
2009-04-01	81.6
2009-07-01	82.5
2009-10-01	81.4
2010-01-01	80
2010-04-01	83.6
2010-07-01	82.8
2010-10-01	80.9
2011-01-01	81.3
2011-04-01	85.2
2011-07-01	81.8
2011-10-01	78.6
2012-01-01	80.4
2012-04-01	85.3
2012-07-01	83.3
2012-10-01	81.5
2013-01-01	81.4
2013-04-01	84.9
2013-07-01	84.4
2013-10-01	82.6
2014-01-01	82.1
2014-04-01	86.7
2014-07-01	85.8
2014-10-01	84.1
2015-01-01	84.4
2015-04-01	87.9
2015-07-01	85.8
2015-10-01	85.4
2016-01-01	84.4
2016-04-01	88.1
2016-07-01	87.1
2016-10-01	85.7
2017-01-01	85.6
2017-04-01	87.9
2017-07-01	85.4
2017-10-01	84.6
2018-01-01	83.5
2018-04-01	85.2