Quarter	Percent
1998-01-01	94.2
1998-04-01	94.5
1998-07-01	94.5
1998-10-01	94.3
1999-01-01	94.7
1999-04-01	94.6
1999-07-01	94.5
1999-10-01	94.2
2000-01-01	94.3
2000-04-01	94.5
2000-07-01	94.4
2000-10-01	94.2
2001-01-01	94.1
2001-04-01	94.2
2001-07-01	94.1
2001-10-01	94.1
2002-01-01	93.8
2002-04-01	94.2
2002-07-01	94.2
2002-10-01	94.2
2003-01-01	94.4
2003-04-01	94.2
2003-07-01	94.4
2003-10-01	94.3
2004-01-01	94.5
2004-04-01	94.7
2004-07-01	94.7
2004-10-01	94.5
2005-01-01	94.5
2005-04-01	94.7
2005-07-01	94.6
2005-10-01	94.6
2006-01-01	94.7
2006-04-01	94.6
2006-07-01	94.8
2006-10-01	94.8
2007-01-01	94.6
2007-04-01	94.5
2007-07-01	94.7
2007-10-01	94.6
2008-01-01	94.7
2008-04-01	94.7
2008-07-01	94.2
2008-10-01	93.9
2009-01-01	94.2
2009-04-01	94.4
2009-07-01	94.7
2009-10-01	94.3
2010-01-01	94.5
2010-04-01	94.4
2010-07-01	94.1
2010-10-01	93.8
2011-01-01	93.5
2011-04-01	93.6
2011-07-01	93.7
2011-10-01	93.2
2012-01-01	93.4
2012-04-01	93.6
2012-07-01	93.7
2012-10-01	93.6
2013-01-01	93.5
2013-04-01	93.8
2013-07-01	93.6
2013-10-01	93.4
2014-01-01	93.4
2014-04-01	93.3
2014-07-01	93.2
2014-10-01	92.6
2015-01-01	92.5
2015-04-01	93.0
2015-07-01	93.6
2015-10-01	93.3
2016-01-01	93.0
2016-04-01	93.5
2016-07-01	93.4
2016-10-01	92.7
2017-01-01	92.8
2017-04-01	93.1
2017-07-01	93.3
2017-10-01	92.8
2018-01-01	92.9
2018-04-01	93.3