Quarter	Percent
2005-01-01	42.7
2005-04-01	43.4
2005-07-01	43.7
2005-10-01	43.9
2006-01-01	43.8
2006-04-01	44.6
2006-07-01	45.0
2006-10-01	45.1
2007-01-01	44.8
2007-04-01	45.5
2007-07-01	45.4
2007-10-01	45.8
2008-01-01	45.5
2008-04-01	46.2
2008-07-01	46.0
2008-10-01	46.4
2009-01-01	46.4
2009-04-01	47.3
2009-07-01	47.2
2009-10-01	47.2
2010-01-01	47.3
2010-04-01	48.0
2010-07-01	48.2
2010-10-01	47.9
2011-01-01	48.0
2011-04-01	48.8
2011-07-01	48.8
2011-10-01	48.9
2012-01-01	49.0
2012-04-01	49.8
2012-07-01	49.6
2012-10-01	50.0
2013-01-01	50.1
2013-04-01	50.7
2013-07-01	50.7
2013-10-01	51.0
2014-01-01	51.0
2014-04-01	51.6
2014-07-01	51.5
2014-10-01	51.8
2015-01-01	51.7
2015-04-01	52.2
2015-07-01	52.4
2015-10-01	52.8
2016-01-01	52.9
2016-04-01	53.3
2016-07-01	53.3
2016-10-01	53.7
2017-01-01	53.9
2017-04-01	54.3