Quarter	Percent
1999-04-01	73.5
2000-01-01	72.6
2000-04-01	73.8
2000-07-01	73.7
2000-10-01	72.7
2001-01-01	72.7
2001-04-01	73.9
2001-07-01	73.7
2001-10-01	73.1
2002-01-01	73.1
2002-04-01	74.1
2002-07-01	73.7
2002-10-01	72.5
2003-01-01	72.1
2003-04-01	72.8
2003-07-01	73
2003-10-01	72
2004-01-01	71.5
2004-04-01	72.6
2004-07-01	73
2004-10-01	72
2005-01-01	71.5
2005-04-01	72.3
2005-07-01	72.8
2005-10-01	72.1
2006-01-01	71.3
2006-04-01	72.1
2006-07-01	72.3
2006-10-01	71.6
2007-01-01	71.8
2007-04-01	72.7
2007-07-01	73
2007-10-01	73.1
2008-01-01	73.4
2008-04-01	74.3
2008-07-01	74.2
2008-10-01	73.2
2009-01-01	72.9
2009-04-01	73.4
2009-07-01	72.5
2009-10-01	71.7
2010-01-01	71.7
2010-04-01	72.4
2010-07-01	71.8
2010-10-01	71.3
2011-01-01	70.9
2011-04-01	71.6
2011-07-01	71.6
2011-10-01	71.2
2012-01-01	71.3
2012-04-01	72
2012-07-01	71.5
2012-10-01	70.9
2013-01-01	70.8
2013-04-01	71.4
2013-07-01	71.4
2013-10-01	70.7
2014-01-01	64.4
2014-04-01	65.1
2014-07-01	65.1
2014-10-01	64.8
2015-01-01	64.6
2015-04-01	65.4
2015-07-01	65.3
2015-10-01	64.5
2016-01-01	64.7
2016-04-01	64.7
2016-07-01	65.0
2016-10-01	63.7
2017-01-01	63.6
2017-04-01	64.1
2017-07-01	63.9
2017-10-01	63.3
2018-01-01	63.5
2018-04-01	64.2