Quarter	Percent
2006-01-01	53.3
2006-04-01	50.4
2006-07-01	49.5
2006-10-01	50.8
2007-01-01	52.6
2007-04-01	50
2007-07-01	49.5
2007-10-01	51.6
2008-01-01	52.5
2008-04-01	49.5
2008-07-01	48.7
2008-10-01	50
2009-01-01	51.5
2009-04-01	48.9
2009-07-01	47.6
2009-10-01	48.9
2010-01-01	49.5
2010-04-01	47.4
2010-07-01	47.1
2010-10-01	48.3
2011-01-01	48.4
2011-04-01	46.1
2011-07-01	45.5
2011-10-01	47.2
2012-01-01	48.8
2012-04-01	46.1
2012-07-01	45.8
2012-10-01	45.9
2013-01-01	47
2013-04-01	44.7
2013-07-01	44.8
2013-10-01	46
2014-01-01	46.4
2014-04-01	44.2
2014-07-01	44.1
2014-10-01	44.9
2015-01-01	45.4
2015-04-01	43.5
2015-07-01	43.0
2015-10-01	44.0
2016-01-01	44.4
2016-04-01	42.6
2016-07-01	42.3
2016-10-01	42.9
2017-01-01	43.2
2017-04-01	41.8
2017-07-01	41.1
2017-10-01	42.0
2018-01-01	42.7
2018-04-01	41.5