Quarter	Percent
1998-04-01	36.8
1999-01-01	38.7
1999-04-01	38.8
1999-07-01	39.1
1999-10-01	38.9
2000-01-01	39
2000-04-01	40
2000-07-01	40.1
2000-10-01	39.5
2001-01-01	39.3
2001-04-01	39
2001-07-01	39.2
2001-10-01	39.2
2002-01-01	39
2002-04-01	39.3
2002-07-01	39.8
2002-10-01	39.9
2003-01-01	39.6
2003-04-01	39.5
2003-07-01	39.6
2003-10-01	40.5
2004-01-01	40
2004-04-01	40.6
2004-07-01	39.5
2004-10-01	40.9
2005-01-01	41.3
2005-04-01	41.5
2005-07-01	41
2005-10-01	41.6
2006-01-01	41.1
2006-04-01	41.3
2006-07-01	41.7
2006-10-01	42.1
2007-01-01	42
2007-04-01	42.3
2007-07-01	42.5
2007-10-01	43.6
2008-01-01	43.5
2008-04-01	43
2008-07-01	43.7
2008-10-01	43.1
2009-01-01	43.1
2009-04-01	43.1
2009-07-01	43
2009-10-01	43.4
2010-01-01	43.9
2010-04-01	42.8
2010-07-01	43.5
2010-10-01	44.4
2011-01-01	43.2
2011-04-01	44
2011-07-01	43.7
2011-10-01	43.7
2012-01-01	43.2
2012-04-01	43.2
2012-07-01	43.9
2012-10-01	44.2
2013-01-01	43.4
2013-04-01	43.5
2013-07-01	44.7
2013-10-01	43.8
2014-01-01	43.7
2014-04-01	44.4
2014-07-01	44.6
2014-10-01	44.4
2015-01-01	44.4
2015-04-01	43.9
2015-07-01	44.2
2015-10-01	44.6
2016-01-01	43.9
2016-04-01	43.5
2016-07-01	43.8
2016-10-01	45.5
2017-01-01	44.5
2017-04-01	45.0
2017-07-01	45.5
2017-10-01	46.1
2018-01-01	46.3
2018-04-01	45.9