Quarter	Percent
1998-01-01	44
1998-04-01	44
1998-07-01	43.7
1998-10-01	43.9
1999-01-01	43.3
1999-04-01	43.6
1999-07-01	43.8
1999-10-01	43.9
2000-01-01	43.9
2000-04-01	43.7
2000-07-01	43.6
2000-10-01	44
2001-01-01	44.2
2001-04-01	44.3
2001-07-01	44.4
2001-10-01	44.6
2002-01-01	44.3
2002-04-01	43.7
2002-07-01	43.4
2002-10-01	43.4
2003-01-01	43.2
2003-04-01	43.1
2003-07-01	42.8
2003-10-01	42.9
2004-01-01	42.3
2004-04-01	42
2004-07-01	42
2004-10-01	42
2005-01-01	42.1
2005-04-01	41.8
2005-07-01	41.7
2005-10-01	41.7
2006-01-01	41.5
2006-04-01	41.5
2006-07-01	41.3
2006-10-01	41.5
2007-01-01	41.5
2007-04-01	41.4
2007-07-01	41.2
2007-10-01	41.4
2008-01-01	41.3
2008-04-01	41.1
2008-07-01	41
2008-10-01	41
2009-01-01	40.7
2009-04-01	40.4
2009-07-01	40
2009-10-01	40.3
2010-01-01	40
2010-04-01	40
2010-07-01	39.9
2010-10-01	40.2
2011-01-01	40.5
2011-04-01	40.7
2011-07-01	40.8
2011-10-01	40.8
2012-01-01	40.9
2012-04-01	40.8
2012-07-01	40.8
2012-10-01	40.7
2013-01-01	41
2013-04-01	40.7
2013-07-01	40.7
2013-10-01	41.1
2014-01-01	40.9
2014-04-01	40.9
2014-07-01	40.8
2014-10-01	41.2
2015-01-01	41.1
2015-04-01	40.7
2015-07-01	40.3
2015-10-01	40.4
2016-01-01	40.5
2016-04-01	40.3
2016-07-01	40.0
2016-10-01	40.6
2017-01-01	40.6
2017-04-01	40.1
2017-07-01	40.2
2017-10-01	40.8
2018-01-01	40.9
2018-04-01	40.3