Quarter	Percent
2006-01-01	27.5
2006-04-01	30.5
2006-07-01	32.4
2006-10-01	30.9
2007-01-01	28.1
2007-04-01	30.7
2007-07-01	32.5
2007-10-01	29.5
2008-01-01	28.3
2008-04-01	30.9
2008-07-01	32.4
2008-10-01	29.5
2009-01-01	25.9
2009-04-01	28.5
2009-07-01	32.3
2009-10-01	29
2010-01-01	27.1
2010-04-01	30.4
2010-07-01	32.5
2010-10-01	29.9
2011-01-01	29.5
2011-04-01	32.1
2011-07-01	34.5
2011-10-01	32
2012-01-01	28.8
2012-04-01	31.9
2012-07-01	33.7
2012-10-01	31.7
2013-01-01	29.8
2013-04-01	33.3
2013-07-01	35.1
2013-10-01	30.7
2014-01-01	31.8
2014-04-01	34.8
2014-07-01	35.4
2014-10-01	32.1
2015-01-01	31.2
2015-04-01	34.4
2015-07-01	37.5
2015-10-01	33.2
2016-01-01	32.4
2016-04-01	35.3
2016-07-01	36.1
2016-10-01	32.6
2017-01-01	31.3
2017-04-01	34.8
2017-07-01	37.0
2017-10-01	34.3
2018-01-01	33.3
2018-04-01	35.5