Quarter	Percent
2006-01-01	26.6
2006-04-01	30.2
2006-07-01	30.5
2006-10-01	27.5
2007-01-01	26.6
2007-04-01	30.2
2007-07-01	28.7
2007-10-01	27.1
2008-01-01	26
2008-04-01	30.5
2008-07-01	30.5
2008-10-01	27.9
2009-01-01	27.7
2009-04-01	30.4
2009-07-01	30.7
2009-10-01	30.8
2010-01-01	30
2010-04-01	32.4
2010-07-01	31.6
2010-10-01	30.5
2011-01-01	31
2011-04-01	33.7
2011-07-01	34
2011-10-01	32.4
2012-01-01	31
2012-04-01	34
2012-07-01	33.7
2012-10-01	33.8
2013-01-01	31.5
2013-04-01	34.2
2013-07-01	33.6
2013-10-01	32.7
2014-01-01	31.1
2014-04-01	34.7
2014-07-01	34.1
2014-10-01	33.7
2015-01-01	32.3
2015-04-01	35.4
2015-07-01	34.5
2015-10-01	34.2
2016-01-01	34.7
2016-04-01	36.7
2016-07-01	35.7
2016-10-01	35.5
2017-01-01	35.5
2017-04-01	36.6
2017-07-01	37.5
2017-10-01	37.7
2018-01-01	36.5
2018-04-01	38.4