Quarter	Percent
1998-04-01	64.6
1999-04-01	65.7
2000-04-01	66.4
2001-01-01	68.1
2001-04-01	69.5
2001-07-01	70.2
2001-10-01	68.7
2002-01-01	67.7
2002-04-01	69.1
2002-07-01	69.5
2002-10-01	67.9
2003-01-01	66.8
2003-04-01	68.5
2003-07-01	69.1
2003-10-01	67.2
2004-01-01	66.2
2004-04-01	67.6
2004-07-01	68.2
2004-10-01	66.6
2005-01-01	65.8
2005-04-01	68.2
2005-07-01	69.1
2005-10-01	67.8
2006-01-01	67.1
2006-04-01	68.7
2006-07-01	70.1
2006-10-01	68.9
2007-01-01	68.4
2007-04-01	69.8
2007-07-01	71
2007-10-01	69.4
2008-01-01	68.9
2008-04-01	70.3
2008-07-01	71
2008-10-01	68.8
2009-01-01	66.9
2009-04-01	67.4
2009-07-01	67.9
2009-10-01	66.5
2010-01-01	65.8
2010-04-01	67.7
2010-07-01	68.8
2010-10-01	67.6
2011-01-01	67.1
2011-04-01	68.5
2011-07-01	69.3
2011-10-01	67.6
2012-01-01	66.6
2012-04-01	68.2
2012-07-01	69
2012-10-01	67.7
2013-01-01	67
2013-04-01	68.2
2013-07-01	69.5
2013-10-01	68
2014-01-01	67.1
2014-04-01	68.7
2014-07-01	70
2014-10-01	68.6
2015-01-01	67.7
2015-04-01	68.9
2015-07-01	69.9
2015-10-01	68.7
2016-01-01	67.7
2016-04-01	69.4
2016-07-01	69.9
2016-10-01	68.9
2017-01-01	68.5
2017-04-01	70.1
2017-07-01	71.2
2017-10-01	69.9
2018-01-01	69.5
2018-04-01	70.6