Quarter	Percent
2000-04-01	51.4
2001-04-01	51.6
2002-04-01	51.3
2003-04-01	51.4
2004-04-01	51.3
2005-01-01	51.3
2005-04-01	51.8
2005-07-01	52.1
2005-10-01	52
2006-01-01	51.8
2006-04-01	52.5
2006-07-01	53
2006-10-01	52.7
2007-01-01	52.4
2007-04-01	53.1
2007-07-01	53.6
2007-10-01	53.4
2008-01-01	53.1
2008-04-01	53.5
2008-07-01	53.9
2008-10-01	53.4
2009-01-01	52.3
2009-04-01	52.4
2009-07-01	52.4
2009-10-01	52.1
2010-01-01	51.4
2010-04-01	52
2010-07-01	52.2
2010-10-01	51.9
2011-01-01	51.5
2011-04-01	52.0
2011-07-01	52.1
2011-10-01	51.7
2012-01-01	51.2
2012-04-01	51.7
2012-07-01	51.9
2012-10-01	51.5
2013-01-01	50.8
2013-04-01	51.4
2013-07-01	51.7
2013-10-01	51.5
2014-01-01	51.1
2014-04-01	51.7
2014-07-01	52.2
2014-10-01	51.9
2015-01-01	51.5
2015-04-01	52.1
2015-07-01	52.6
2015-10-01	52.5
2016-01-01	52.2
2016-04-01	52.8
2016-07-01	53.2
2016-10-01	53.0
2017-01-01	52.8
2017-04-01	53.6
2017-07-01	53.9
2017-10-01	53.8
2018-01-01	53.5
2018-04-01	54.1