Quarter	Percent
1999-04-01	46.2
2000-04-01	46.1
2001-04-01	46.5
2002-04-01	45.4
2003-04-01	44
2004-04-01	41.3
2005-01-01	41.4
2005-04-01	41.1
2005-07-01	42
2005-10-01	43.1
2006-01-01	43.1
2006-04-01	42.9
2006-07-01	43.2
2006-10-01	44.9
2007-01-01	45.4
2007-04-01	43.8
2007-07-01	45.9
2007-10-01	46.6
2008-01-01	47.2
2008-04-01	45.6
2008-07-01	46.7
2008-10-01	47.1
2009-01-01	46.1
2009-04-01	45
2009-07-01	46.3
2009-10-01	46.5
2010-01-01	45.4
2010-04-01	45.2
2010-07-01	46.7
2010-10-01	47.7
2011-01-01	47.1
2011-04-01	47.2
2011-07-01	48.2
2011-10-01	49.2
2012-01-01	46.3
2012-04-01	45.8
2012-07-01	46.8
2012-10-01	47.5
2013-01-01	47
2013-04-01	46.2
2013-07-01	47
2013-10-01	47.3
2014-01-01	46
2014-04-01	44.8
2014-07-01	46.4
2014-10-01	47
2015-01-01	46.3
2015-04-01	43.8
2015-07-01	44.6
2015-10-01	46.5
2016-01-01	45.1
2016-04-01	44.0
2016-07-01	46.5
2016-10-01	47.5
2017-01-01	45.9
2017-04-01	45.0
2017-07-01	46.9
2017-10-01	48.2
2018-01-01	46.6
2018-04-01	45.7