Quarter	Percent
1998-04-01	36.5
1998-10-01	36.1
1999-04-01	36.6
1999-10-01	36.9
2000-04-01	35.4
2000-10-01	36.5
2001-04-01	35.9
2001-10-01	37.8
2002-01-01	38.7
2002-04-01	42.9
2002-07-01	42.5
2002-10-01	42.9
2003-01-01	42.2
2003-04-01	40.8
2003-07-01	48.2
2003-10-01	41.9
2004-01-01	48.0
2004-04-01	44.7
2004-07-01	47.5
2004-10-01	46.1
2005-01-01	47.1
2005-04-01	46.9
2005-07-01	50.6
2005-10-01	48.8
2006-01-01	51.9
2006-04-01	53.5
2006-07-01	54.2
2006-10-01	54.2
2007-01-01	57.6
2007-04-01	57.1
2007-07-01	58.2
2007-10-01	59.1
2008-01-01	59.7
2008-04-01	59.4
2008-07-01	59.4
2008-10-01	57.7
2009-01-01	57.9
2009-04-01	56.7
2009-07-01	47.8
2009-10-01	47.6
2010-01-01	47.2
2010-04-01	49.5
2010-07-01	47.0
2010-10-01	47.5
2011-01-01	48.6
2011-04-01	50.4
2011-07-01	50.7
2011-10-01	52.5
2012-01-01	50.9
2012-04-01	52.3
2012-07-01	54.7
2012-10-01	53.2
2013-01-01	53.2
2013-04-01	55.2
2013-07-01	56.6
2013-10-01	54.2
2014-01-01	56.0
2014-04-01	57.3
2014-07-01	55.8
2014-10-01	56.5
2015-01-01	58.7
2015-04-01	59.0
2015-07-01	59.6
2015-10-01	60.3
2016-01-01	60.2
2016-04-01	62.1
2016-07-01	60.7
2016-10-01	62.4
2017-01-01	60.1
2017-04-01	62.1
2017-07-01	62.9
2017-10-01	63.9
2018-01-01	63.0
2018-04-01	65.3