Quarter	Percent
2006-01-01	25.3
2006-04-01	29.3
2006-07-01	29.6
2006-10-01	26.5
2007-01-01	25.5
2007-04-01	29.3
2007-07-01	27.9
2007-10-01	26
2008-01-01	24.9
2008-04-01	29.4
2008-07-01	29.2
2008-10-01	26.5
2009-01-01	26
2009-04-01	28.6
2009-07-01	29.1
2009-10-01	29.1
2010-01-01	28.1
2010-04-01	30.9
2010-07-01	30.2
2010-10-01	29
2011-01-01	29.2
2011-04-01	32.1
2011-07-01	32.8
2011-10-01	31.2
2012-01-01	29.5
2012-04-01	32.7
2012-07-01	32.8
2012-10-01	32.4
2013-01-01	30.1
2013-04-01	32.7
2013-07-01	32
2013-10-01	31.1
2014-01-01	29.1
2014-04-01	32.7
2014-07-01	32.3
2014-10-01	31.5
2015-01-01	30.1
2015-04-01	33.2
2015-07-01	32.2
2015-10-01	31.7
2016-01-01	32.3
2016-04-01	34.7
2016-07-01	33.5
2016-10-01	33.2
2017-01-01	32.7
2017-04-01	34.2
2017-07-01	35.4
2017-10-01	35.4
2018-01-01	33.6
2018-04-01	36.1