Quarter	Percent
2006-01-01	20.2
2006-04-01	24.1
2006-07-01	24
2006-10-01	22.7
2007-01-01	21.5
2007-04-01	24.3
2007-07-01	23.7
2007-10-01	21.6
2008-01-01	21.1
2008-04-01	24.9
2008-07-01	24.8
2008-10-01	23.2
2009-01-01	21.6
2009-04-01	25
2009-07-01	25.5
2009-10-01	24.8
2010-01-01	24.2
2010-04-01	27.3
2010-07-01	27
2010-10-01	26.2
2011-01-01	25.9
2011-04-01	28.9
2011-07-01	28.9
2011-10-01	27.6
2012-01-01	26.6
2012-04-01	29.9
2012-07-01	29.2
2012-10-01	29.2
2013-01-01	28.4
2013-04-01	31.1
2013-07-01	30
2013-10-01	29.1
2014-01-01	28.1
2014-04-01	30.6
2014-07-01	29.9
2014-10-01	29.4
2015-01-01	28.9
2015-04-01	31.5
2015-07-01	30.9
2015-10-01	30.5
2016-01-01	30.2
2016-04-01	32.5
2016-07-01	31.3
2016-10-01	30.6
2017-01-01	30.7
2017-04-01	32.9
2017-07-01	32.4
2017-10-01	32.7
2018-01-01	32.2
2018-04-01	33.7