Quarter	Percent
2005-01-01	47.8
2005-04-01	46.7
2005-07-01	44.7
2005-10-01	46.9
2006-01-01	47.8
2006-04-01	46.5
2006-07-01	44.5
2006-10-01	46.9
2007-01-01	48.0
2007-04-01	46.8
2007-07-01	45.1
2007-10-01	47.2
2008-01-01	48.3
2008-04-01	46.6
2008-07-01	45.0
2008-10-01	47.9
2009-01-01	49.4
2009-04-01	47.9
2009-07-01	46.7
2009-10-01	49.4
2010-01-01	50.3
2010-04-01	48.7
2010-07-01	47.4
2010-10-01	49.8
2011-01-01	50.5
2011-04-01	49.1
2011-07-01	47.5
2011-10-01	49.4
2012-01-01	50.8
2012-04-01	48.9
2012-07-01	47.4
2012-10-01	49.7
2013-01-01	50.7
2013-04-01	49.1
2013-07-01	47.5
2013-10-01	50.3
2014-01-01	50.7
2014-04-01	49.4
2014-07-01	47.5
2014-10-01	50.0
2015-01-01	50.8
2015-04-01	49.7
2015-07-01	48.0
2015-10-01	49.9
2016-01-01	50.9
2016-04-01	49.3
2016-07-01	47.8
2016-10-01	49.8
2017-01-01	50.7
2017-04-01	49.2