Quarter	Percent
1999-04-01	86.6
2000-04-01	87.4
2001-04-01	86.9
2002-04-01	85.7
2003-04-01	84.4
2004-04-01	83.1
2005-01-01	83
2005-04-01	83.7
2005-07-01	84.2
2005-10-01	83.8
2006-01-01	83.6
2006-04-01	84.6
2006-07-01	85.8
2006-10-01	85.3
2007-01-01	85.4
2007-04-01	86.6
2007-07-01	87
2007-10-01	86.7
2008-01-01	86.1
2008-04-01	86.7
2008-07-01	88
2008-10-01	87.3
2009-01-01	86
2009-04-01	85.9
2009-07-01	86
2009-10-01	86.5
2010-01-01	85.6
2010-04-01	86.8
2010-07-01	87.4
2010-10-01	87.3
2011-01-01	86.9
2011-04-01	88
2011-07-01	88.4
2011-10-01	88.6
2012-01-01	87.6
2012-04-01	88.5
2012-07-01	88.8
2012-10-01	88.6
2013-01-01	87.3
2013-04-01	88.4
2013-07-01	88.3
2013-10-01	88.7
2014-01-01	87.4
2014-04-01	88
2014-07-01	88.5
2014-10-01	88.3
2015-01-01	87.7
2015-04-01	88.0
2015-07-01	88.4
2015-10-01	88.5
2016-01-01	87.6
2016-04-01	88.1
2016-07-01	88.4
2016-10-01	88.1
2017-01-01	87.8
2017-04-01	88.3
2017-07-01	88.6
2017-10-01	88.6
2018-01-01	88.6
2018-04-01	88.8