Quarter	Percent
1999-04-01	85.7
2000-04-01	86.7
2001-04-01	87.1
2002-04-01	84.4
2003-01-01	80
2003-04-01	83.8
2003-07-01	84.1
2003-10-01	81.1
2004-01-01	79.3
2004-04-01	82.4
2004-07-01	84.1
2004-10-01	82.2
2005-01-01	79.5
2005-04-01	85.1
2005-07-01	86.5
2005-10-01	82
2006-01-01	82.4
2006-04-01	85.7
2006-07-01	86
2006-10-01	84.3
2007-01-01	84.2
2007-04-01	85.5
2007-07-01	86.4
2007-10-01	85
2008-01-01	83.2
2008-04-01	85.8
2008-07-01	84.9
2008-10-01	80.8
2009-01-01	75.5
2009-04-01	76.7
2009-07-01	79.3
2009-10-01	76.1
2010-01-01	75.2
2010-04-01	78.2
2010-07-01	78.1
2010-10-01	76.3
2011-01-01	73.8
2011-04-01	77
2011-07-01	78.7
2011-10-01	77.3
2012-01-01	75.4
2012-04-01	78.3
2012-07-01	79.2
2012-10-01	76.7
2013-01-01	76
2013-04-01	79.7
2013-07-01	81.3
2013-10-01	78.8
2014-01-01	78.2
2014-04-01	82.5
2014-07-01	83.4
2014-10-01	81.2
2015-01-01	81.1
2015-04-01	84.2
2015-07-01	85.0
2015-10-01	81.3
2016-01-01	83.0
2016-04-01	86.3
2016-07-01	86.7
2016-10-01	84.7
2017-01-01	84.4
2017-04-01	86.1
2017-07-01	84.4
2017-10-01	82.2
2018-01-01	81.9
2018-04-01	84.0