Quarter	Percent
1999-01-01	83.7
1999-04-01	84.4
1999-07-01	84.6
1999-10-01	84.6
2000-01-01	83.8
2000-04-01	84.3
2000-07-01	84.8
2000-10-01	84.8
2001-01-01	83.9
2001-04-01	84.3
2001-07-01	84.5
2001-10-01	84.1
2002-01-01	83.8
2002-04-01	84.3
2002-07-01	84.7
2002-10-01	84.5
2003-01-01	83.8
2003-04-01	84.9
2003-07-01	85.4
2003-10-01	85.2
2004-01-01	84.6
2004-04-01	85.1
2004-07-01	85.3
2004-10-01	84.9
2005-01-01	84.5
2005-04-01	85.3
2005-07-01	86.2
2005-10-01	86
2006-01-01	85.9
2006-04-01	87.2
2006-07-01	87.3
2006-10-01	87.3
2007-01-01	86.6
2007-04-01	87.4
2007-07-01	87.6
2007-10-01	87.2
2008-01-01	86.7
2008-04-01	87.4
2008-07-01	88
2008-10-01	87.3
2009-01-01	86.7
2009-04-01	87.4
2009-07-01	87.2
2009-10-01	87.1
2010-01-01	86.6
2010-04-01	87.4
2010-07-01	87.7
2010-10-01	87.5
2011-01-01	87
2011-04-01	88.3
2011-07-01	88.9
2011-10-01	88.7
2012-01-01	88.9
2012-04-01	89.4
2012-07-01	89.8
2012-10-01	89.5
2013-01-01	88.3
2013-04-01	89.8
2013-07-01	90.2
2013-10-01	89.7
2014-01-01	90.5
2014-04-01	91.2
2014-07-01	91.8
2014-10-01	91.4
2015-01-01	91.3
2015-04-01	92.0
2015-07-01	92.4
2015-10-01	92.2
2016-01-01	91.8
2016-04-01	92.6
2016-07-01	92.6
2016-10-01	92.4
2017-01-01	92.5
2017-04-01	93.5
2017-07-01	93.6
2017-10-01	93.4
2018-01-01	93.4
2018-04-01	93.7