Quarter	Percent
2006-01-01	33.9
2006-04-01	35.6
2006-07-01	38.5
2006-10-01	37.1
2007-01-01	34.5
2007-04-01	36.3
2007-07-01	39.3
2007-10-01	35.9
2008-01-01	35.1
2008-04-01	36.4
2008-07-01	39.4
2008-10-01	37.7
2009-01-01	34.6
2009-04-01	36.9
2009-07-01	41
2009-10-01	37.3
2010-01-01	35.4
2010-04-01	37
2010-07-01	40.2
2010-10-01	36.9
2011-01-01	36.3
2011-04-01	38.3
2011-07-01	41.5
2011-10-01	37.8
2012-01-01	34.5
2012-04-01	37.2
2012-07-01	39.6
2012-10-01	38.1
2013-01-01	36.5
2013-04-01	39.1
2013-07-01	42.2
2013-10-01	37.4
2014-01-01	38.3
2014-04-01	41.3
2014-07-01	43.5
2014-10-01	40
2015-01-01	39.0
2015-04-01	41.3
2015-07-01	45.8
2015-10-01	41.0
2016-01-01	39.7
2016-04-01	42.7
2016-07-01	45.0
2016-10-01	42.0
2017-01-01	40.7
2017-04-01	43.2
2017-07-01	46.5
2017-10-01	42.4
2018-01-01	41.0
2018-04-01	43.1