Quarter	Percent
2005-01-01	31.2
2005-04-01	31.1
2005-07-01	31.4
2005-10-01	31.7
2006-01-01	32.3
2006-04-01	32.3
2006-07-01	32.0
2006-10-01	33.2
2007-01-01	32.5
2007-04-01	31.6
2007-07-01	31.1
2007-10-01	32.9
2008-01-01	32.7
2008-04-01	32.2
2008-07-01	30.6
2008-10-01	30.7
2009-01-01	30.9
2009-04-01	30.2
2009-07-01	29.8
2009-10-01	30.6
2010-01-01	30.9
2010-04-01	30.5
2010-07-01	29.0
2010-10-01	28.6
2011-01-01	28.8
2011-04-01	28.4
2011-07-01	28.4
2011-10-01	28.9
2012-01-01	28.8
2012-04-01	28.1
2012-07-01	27.7
2012-10-01	28.1
2013-01-01	28.1
2013-04-01	27.6
2013-07-01	27.4
2013-10-01	27.3
2014-01-01	26.5
2014-04-01	26.4
2014-07-01	25.9
2014-10-01	26.3
2015-01-01	26.6
2015-04-01	25.9
2015-07-01	25.7
2015-10-01	25.3
2016-01-01	25.3
2016-04-01	24.2
2016-07-01	24.2
2016-10-01	24.4
2017-01-01	24.7
2017-04-01	23.9
2017-07-01	23.9
2017-10-01	23.7
2018-01-01	23.8
2018-04-01	23.2