Quarter	Percent
2005-01-01	30.0
2005-04-01	29.4
2005-07-01	29.1
2005-10-01	29.5
2006-01-01	30.0
2006-04-01	29.4
2006-07-01	29.1
2006-10-01	29.4
2007-01-01	30.0
2007-04-01	29.4
2007-07-01	29.2
2007-10-01	29.6
2008-01-01	30.1
2008-04-01	29.4
2008-07-01	29.2
2008-10-01	29.8
2009-01-01	30.4
2009-04-01	30.0
2009-07-01	29.9
2009-10-01	30.5
2010-01-01	30.8
2010-04-01	30.3
2010-07-01	30.2
2010-10-01	30.8
2011-01-01	31.1
2011-04-01	30.6
2011-07-01	30.4
2011-10-01	30.8
2012-01-01	31.3
2012-04-01	30.6
2012-07-01	30.5
2012-10-01	30.9
2013-01-01	31.4
2013-04-01	30.8
2013-07-01	30.7
2013-10-01	31.3
2014-01-01	31.6
2014-04-01	31.1
2014-07-01	30.9
2014-10-01	31.4
2015-01-01	31.6
2015-04-01	31.2
2015-07-01	31.1
2015-10-01	31.4
2016-01-01	31.6
2016-04-01	31.1
2016-07-01	30.9
2016-10-01	31.3
2017-01-01	31.6
2017-04-01	31.1