Quarter	Percent
1999-04-01	93.6
2000-04-01	93.7
2001-04-01	93.5
2002-04-01	93.3
2003-04-01	93.2
2004-04-01	92.9
2005-01-01	93.6
2005-04-01	93.8
2005-07-01	93.6
2005-10-01	93.3
2006-01-01	93.7
2006-04-01	93.7
2006-07-01	93.9
2006-10-01	93.6
2007-01-01	93.9
2007-04-01	93.7
2007-07-01	93.9
2007-10-01	93.6
2008-01-01	93.4
2008-04-01	93.4
2008-07-01	93.8
2008-10-01	93.4
2009-01-01	93.3
2009-04-01	93.2
2009-07-01	93.1
2009-10-01	93.2
2010-01-01	93.1
2010-04-01	93.2
2010-07-01	93.4
2010-10-01	93.1
2011-01-01	93
2011-04-01	93.2
2011-07-01	93.3
2011-10-01	93.3
2012-01-01	93.1
2012-04-01	93.1
2012-07-01	93.3
2012-10-01	93.1
2013-01-01	92.8
2013-04-01	93
2013-07-01	92.8
2013-10-01	93
2014-01-01	92.5
2014-04-01	92.5
2014-07-01	92.9
2014-10-01	92.6
2015-01-01	92.5
2015-04-01	92.3
2015-07-01	92.5
2015-10-01	92.6
2016-01-01	91.9
2016-04-01	92.0
2016-07-01	92.1
2016-10-01	91.8
2017-01-01	91.8
2017-04-01	92.0
2017-07-01	92.0
2017-10-01	91.9
2018-01-01	92.3
2018-04-01	92.2