Quarter	Percent
1998-01-01	39.5
1998-04-01	49.7
1998-07-01	51.1
1998-10-01	40.3
1999-01-01	42.1
1999-04-01	63
1999-07-01	55.6
1999-10-01	43.1
2000-01-01	45.8
2000-04-01	63.3
2000-07-01	55.9
2000-10-01	44.1
2001-01-01	45.3
2001-04-01	62.9
2001-07-01	55.4
2001-10-01	44.7
2002-01-01	44.7
2002-04-01	62.3
2002-07-01	54.6
2002-10-01	44.2
2003-01-01	45.9
2003-04-01	61.4
2003-07-01	54.3
2003-10-01	41.1
2004-01-01	42.7
2004-04-01	59.8
2004-07-01	53.4
2004-10-01	43
2005-01-01	44.6
2005-04-01	60.2
2005-07-01	52.6
2005-10-01	45.3
2006-01-01	46
2006-04-01	60.8
2006-07-01	55
2006-10-01	45.5
2007-01-01	46.3
2007-04-01	62.1
2007-07-01	56.9
2007-10-01	48.4
2008-01-01	47.4
2008-04-01	63.9
2008-07-01	55
2008-10-01	47.6
2009-01-01	46.4
2009-04-01	62.2
2009-07-01	49.8
2009-10-01	43.3
2010-01-01	43.8
2010-04-01	59.4
2010-07-01	50.8
2010-10-01	43.4
2011-01-01	44.9
2011-04-01	61.2
2011-07-01	52.9
2011-10-01	43.1
2012-01-01	45.5
2012-04-01	61.3
2012-07-01	54.1
2012-10-01	45.4
2013-01-01	46.7
2013-04-01	62.5
2013-07-01	52.3
2013-10-01	45.8
2014-01-01	46.9
2014-04-01	62.3
2014-07-01	52.7
2014-10-01	46.4
2015-01-01	47.7
2015-04-01	62.9
2015-07-01	53.6
2015-10-01	44.5
2016-01-01	47.1
2016-04-01	61.8
2016-07-01	54.3
2016-10-01	45.6
2017-01-01	48.0
2017-04-01	62.2
2017-07-01	55.9
2017-10-01	46.8
2018-01-01	49.0
2018-04-01	63.2