Quarter	Percent
1998-04-01	35.1
1999-04-01	35.8
2000-04-01	36.6
2001-01-01	41
2001-04-01	45.6
2001-07-01	48.1
2001-10-01	40.2
2002-01-01	37.7
2002-04-01	43.7
2002-07-01	46.4
2002-10-01	39.3
2003-01-01	36.6
2003-04-01	42.7
2003-07-01	45.3
2003-10-01	36.9
2004-01-01	34.3
2004-04-01	39.2
2004-07-01	43.9
2004-10-01	37.1
2005-01-01	35.4
2005-04-01	39.2
2005-07-01	42.2
2005-10-01	36
2006-01-01	34.7
2006-04-01	40.8
2006-07-01	45.3
2006-10-01	39.8
2007-01-01	38.6
2007-04-01	41.6
2007-07-01	47.4
2007-10-01	40.5
2008-01-01	39.1
2008-04-01	43.2
2008-07-01	47.4
2008-10-01	39.3
2009-01-01	35.4
2009-04-01	39.6
2009-07-01	41.1
2009-10-01	34.5
2010-01-01	32.8
2010-04-01	39.3
2010-07-01	43.9
2010-10-01	38
2011-01-01	37
2011-04-01	42.4
2011-07-01	45.6
2011-10-01	38.2
2012-01-01	35
2012-04-01	39.7
2012-07-01	43.3
2012-10-01	37.2
2013-01-01	35.9
2013-04-01	40.8
2013-07-01	46.1
2013-10-01	39.4
2014-01-01	37.7
2014-04-01	41.7
2014-07-01	46.9
2014-10-01	40.1
2015-01-01	38.8
2015-04-01	42.4
2015-07-01	46.8
2015-10-01	41.7
2016-01-01	39.1
2016-04-01	44.7
2016-07-01	46.6
2016-10-01	41.9
2017-01-01	39.8
2017-04-01	44.7
2017-07-01	48.5
2017-10-01	42.6
2018-01-01	40.8
2018-04-01	43.7