Quarter	Percent
1998-04-01	31.8
1999-04-01	35
2000-04-01	37.1
2001-01-01	39.8
2001-04-01	47
2001-07-01	49.7
2001-10-01	42.2
2002-01-01	40.9
2002-04-01	44.3
2002-07-01	48.8
2002-10-01	41.4
2003-01-01	40.1
2003-04-01	44.1
2003-07-01	45.8
2003-10-01	38.4
2004-01-01	36.6
2004-04-01	39.9
2004-07-01	44.9
2004-10-01	37.4
2005-01-01	34.4
2005-04-01	41.2
2005-07-01	45
2005-10-01	38.3
2006-01-01	34.5
2006-04-01	40.6
2006-07-01	47.7
2006-10-01	38.8
2007-01-01	37.4
2007-04-01	42.6
2007-07-01	48.5
2007-10-01	40.6
2008-01-01	39
2008-04-01	43.3
2008-07-01	47.2
2008-10-01	38.8
2009-01-01	36.8
2009-04-01	41.2
2009-07-01	41.4
2009-10-01	36.1
2010-01-01	34.8
2010-04-01	40.2
2010-07-01	44.1
2010-10-01	37.6
2011-01-01	36.9
2011-04-01	41.5
2011-07-01	46.1
2011-10-01	39.6
2012-01-01	38.2
2012-04-01	42.9
2012-07-01	46.3
2012-10-01	38.9
2013-01-01	38.1
2013-04-01	43.7
2013-07-01	47.4
2013-10-01	42.3
2014-01-01	39.4
2014-04-01	44.4
2014-07-01	50.5
2014-10-01	41.8
2015-01-01	41.2
2015-04-01	45.8
2015-07-01	51.4
2015-10-01	43.6
2016-01-01	43.5
2016-04-01	47.9
2016-07-01	49.3
2016-10-01	43.1
2017-01-01	43.0
2017-04-01	46.5
2017-07-01	49.9
2017-10-01	44.5
2018-01-01	43.0
2018-04-01	48.5