Quarter	Percent
1998-01-01	67.0
1998-04-01	67.1
1998-07-01	66.9
1998-10-01	66.6
1999-01-01	65.2
1999-04-01	65
1999-07-01	65.1
1999-10-01	64.8
2000-01-01	63.9
2000-04-01	64.3
2000-07-01	64.5
2000-10-01	64.5
2001-01-01	64
2001-04-01	64.3
2001-07-01	64.4
2001-10-01	64.6
2002-01-01	64.3
2002-04-01	64.9
2002-07-01	65.2
2002-10-01	65.2
2003-01-01	64.4
2003-04-01	64.3
2003-07-01	64.2
2003-10-01	64
2004-01-01	63
2004-04-01	63.3
2004-07-01	63.7
2004-10-01	63.9
2005-01-01	63.5
2005-04-01	64.3
2005-07-01	64.7
2005-10-01	64.6
2006-01-01	64
2006-04-01	64.5
2006-07-01	64.8
2006-10-01	64.9
2007-01-01	64.8
2007-04-01	65.2
2007-07-01	65.8
2007-10-01	66
2008-01-01	65.5
2008-04-01	65.8
2008-07-01	66
2008-10-01	66.1
2009-01-01	64.7
2009-04-01	64.5
2009-07-01	64.1
2009-10-01	64
2010-01-01	62.8
2010-04-01	63.7
2010-07-01	64.3
2010-10-01	64
2011-01-01	63
2011-04-01	63.7
2011-07-01	64
2011-10-01	63.7
2012-01-01	62.9
2012-04-01	63.6
2012-07-01	64.1
2012-10-01	63.8
2013-01-01	63.3
2013-04-01	64.2
2013-07-01	64.4
2013-10-01	64.3
2014-01-01	64
2014-04-01	64.7
2014-07-01	65.2
2014-10-01	65
2015-01-01	64.4
2015-04-01	65.1
2015-07-01	65.4
2015-10-01	65.7
2016-01-01	65.5
2016-04-01	65.9
2016-07-01	66.4
2016-10-01	66.4
2017-01-01	66.3
2017-04-01	66.8
2017-07-01	67.4
2017-10-01	67.3
2018-01-01	67.2
2018-04-01	67.5