Quarter	Percent
1998-01-01	36.9
1998-04-01	47.4
1998-07-01	47.5
1998-10-01	38.1
1999-01-01	40.4
1999-04-01	60.9
1999-07-01	53.4
1999-10-01	41.6
2000-01-01	45.2
2000-04-01	61.8
2000-07-01	54.3
2000-10-01	42.7
2001-01-01	45
2001-04-01	61.4
2001-07-01	53.6
2001-10-01	43.4
2002-01-01	44.6
2002-04-01	61.1
2002-07-01	54.1
2002-10-01	43.7
2003-01-01	45.8
2003-04-01	60.9
2003-07-01	52.6
2003-10-01	40.6
2004-01-01	41.5
2004-04-01	59.3
2004-07-01	52.1
2004-10-01	42.7
2005-01-01	44.8
2005-04-01	60.2
2005-07-01	51.8
2005-10-01	44.9
2006-01-01	45
2006-04-01	60.8
2006-07-01	52.7
2006-10-01	45.6
2007-01-01	46.6
2007-04-01	61.6
2007-07-01	56.6
2007-10-01	49.5
2008-01-01	48.1
2008-04-01	62.9
2008-07-01	54.7
2008-10-01	48.4
2009-01-01	47.3
2009-04-01	62.5
2009-07-01	50.2
2009-10-01	44.7
2010-01-01	43.3
2010-04-01	59
2010-07-01	50.7
2010-10-01	44.3
2011-01-01	45.1
2011-04-01	60.6
2011-07-01	53.3
2011-10-01	43
2012-01-01	45.2
2012-04-01	61.3
2012-07-01	54.7
2012-10-01	46.9
2013-01-01	49.7
2013-04-01	62.7
2013-07-01	51.5
2013-10-01	47.6
2014-01-01	47.4
2014-04-01	63.1
2014-07-01	54
2014-10-01	45.9
2015-01-01	48.6
2015-04-01	62.8
2015-07-01	55.3
2015-10-01	46.4
2016-01-01	48.0
2016-04-01	61.8
2016-07-01	56.5
2016-10-01	46.2
2017-01-01	49.4
2017-04-01	62.7
2017-07-01	56.5
2017-10-01	48.1
2018-01-01	50.6
2018-04-01	65.5