Quarter	Percent
1998-01-01	43
1998-04-01	43.5
1998-07-01	43.9
1998-10-01	43.4
1999-01-01	42.5
1999-04-01	42.8
1999-07-01	43.8
1999-10-01	43.8
2000-01-01	42
2000-04-01	42.2
2000-07-01	43.6
2000-10-01	43.3
2001-01-01	41.8
2001-04-01	41.2
2001-07-01	42.9
2001-10-01	43.4
2002-01-01	42.5
2002-04-01	42.9
2002-07-01	43
2002-10-01	43.3
2003-01-01	43.6
2003-04-01	44.4
2003-07-01	44.3
2003-10-01	45.3
2004-01-01	42.5
2004-04-01	43.8
2004-07-01	44.3
2004-10-01	45.1
2005-01-01	43.9
2005-04-01	44
2005-07-01	44.1
2005-10-01	45.1
2006-01-01	43.7
2006-04-01	44.8
2006-07-01	45.7
2006-10-01	45.6
2007-01-01	45.3
2007-04-01	46.1
2007-07-01	47.1
2007-10-01	46.4
2008-01-01	45.6
2008-04-01	46.7
2008-07-01	47.4
2008-10-01	47.7
2009-01-01	47.5
2009-04-01	48.6
2009-07-01	48.5
2009-10-01	49.1
2010-01-01	49.3
2010-04-01	49.3
2010-07-01	49.2
2010-10-01	50.3
2011-01-01	50
2011-04-01	49.8
2011-07-01	50.2
2011-10-01	52.2
2012-01-01	52.1
2012-04-01	53.6
2012-07-01	53.9
2012-10-01	54.7
2013-01-01	55.1
2013-04-01	55.6
2013-07-01	57
2013-10-01	58.7
2014-01-01	58.9
2014-04-01	59.9
2014-07-01	60.8
2014-10-01	61.3
2015-01-01	62.3
2015-04-01	63.8
2015-07-01	63.7
2015-10-01	63.4
2016-01-01	64.8
2016-04-01	66.1
2016-07-01	66.1
2016-10-01	66.4
2017-01-01	66.2
2017-04-01	67.0
2017-07-01	67.4
2017-10-01	67.6
2018-01-01	67.6
2018-04-01	68.8