Quarter	Percent
1998-01-01	41
1998-04-01	41.5
1998-07-01	41.8
1998-10-01	41.3
1999-01-01	40.5
1999-04-01	40.8
1999-07-01	41.8
1999-10-01	41.8
2000-01-01	40
2000-04-01	40.3
2000-07-01	41.8
2000-10-01	41.4
2001-01-01	39.9
2001-04-01	39.3
2001-07-01	40.9
2001-10-01	41.7
2002-01-01	40.8
2002-04-01	41.1
2002-07-01	41.2
2002-10-01	41.9
2003-01-01	41.9
2003-04-01	42.6
2003-07-01	42.8
2003-10-01	43.9
2004-01-01	40.6
2004-04-01	42.1
2004-07-01	42.5
2004-10-01	43.2
2005-01-01	42.1
2005-04-01	42.4
2005-07-01	42.8
2005-10-01	43.5
2006-01-01	42.3
2006-04-01	43.7
2006-07-01	44.6
2006-10-01	44.1
2007-01-01	44
2007-04-01	44.9
2007-07-01	45.9
2007-10-01	45.3
2008-01-01	44
2008-04-01	45.2
2008-07-01	45.9
2008-10-01	46.1
2009-01-01	45.6
2009-04-01	46.8
2009-07-01	46.6
2009-10-01	47.4
2010-01-01	47.2
2010-04-01	47.5
2010-07-01	47.5
2010-10-01	48.2
2011-01-01	47.9
2011-04-01	47.8
2011-07-01	48
2011-10-01	49.2
2012-01-01	48.7
2012-04-01	50.5
2012-07-01	51.2
2012-10-01	51.2
2013-01-01	51
2013-04-01	52.2
2013-07-01	53.7
2013-10-01	54.2
2014-01-01	55.1
2014-04-01	56.5
2014-07-01	57.1
2014-10-01	57.3
2015-01-01	58.2
2015-04-01	59.7
2015-07-01	59.8
2015-10-01	59.3
2016-01-01	60.6
2016-04-01	62.1
2016-07-01	62.1
2016-10-01	61.9
2017-01-01	61.4
2017-04-01	62.9
2017-07-01	63.3
2017-10-01	63.6
2018-01-01	63.0
2018-04-01	64.2