Quarter	Percent
2005-01-01	80.2
2005-04-01	80.6
2005-07-01	80.6
2005-10-01	80.7
2006-01-01	80.5
2006-04-01	80.9
2006-07-01	80.9
2006-10-01	81.0
2007-01-01	80.7
2007-04-01	81.1
2007-07-01	81.0
2007-10-01	81.2
2008-01-01	80.9
2008-04-01	81.3
2008-07-01	81.2
2008-10-01	81.3
2009-01-01	81.0
2009-04-01	81.3
2009-07-01	81.2
2009-10-01	81.3
2010-01-01	81.1
2010-04-01	81.5
2010-07-01	81.2
2010-10-01	81.2
2011-01-01	81.0
2011-04-01	81.4
2011-07-01	81.2
2011-10-01	81.4
2012-01-01	81.1
2012-04-01	81.6
2012-07-01	81.5
2012-10-01	81.6
2013-01-01	81.2
2013-04-01	81.7
2013-07-01	81.4
2013-10-01	81.5
2014-01-01	81.4
2014-04-01	81.6
2014-07-01	81.4
2014-10-01	81.6
2015-01-01	81.4
2015-04-01	81.7
2015-07-01	81.5
2015-10-01	81.8
2016-01-01	81.7
2016-04-01	81.9
2016-07-01	81.9
2016-10-01	82.0
2017-01-01	81.9
2017-04-01	82.2