Quarter	Percent
1999-04-01	39.4
2000-04-01	40.1
2001-04-01	41.5
2002-04-01	41.9
2003-01-01	41.6
2003-04-01	41.6
2003-07-01	41.6
2003-10-01	41.6
2004-01-01	42.2
2004-04-01	42.2
2004-07-01	42.2
2004-10-01	42.2
2005-01-01	43.7
2005-04-01	43.7
2005-07-01	43.7
2005-10-01	43.7
2006-01-01	46.3
2006-04-01	46.3
2006-07-01	46.3
2006-10-01	46.3
2007-01-01	47.7
2007-04-01	46.6
2007-07-01	48.1
2007-10-01	49.6
2008-01-01	44.9
2008-04-01	45.8
2008-07-01	44.8
2008-10-01	45
2009-01-01	47.2
2009-04-01	46.4
2009-07-01	47.1
2009-10-01	46.7
2010-01-01	47.1
2010-04-01	46.9
2010-07-01	47.5
2010-10-01	47.4
2011-01-01	47.2
2011-04-01	46.4
2011-07-01	47.3
2011-10-01	47.5
2012-01-01	47.8
2012-04-01	48.6
2012-07-01	49.7
2012-10-01	49.1
2013-01-01	49.5
2013-04-01	49.5
2013-07-01	48.8
2013-10-01	48.7
2014-01-01	51
2014-04-01	50.1
2014-07-01	49.3
2014-10-01	51.1
2015-01-01	50.7
2015-04-01	51.5
2015-07-01	49.5
2015-10-01	50.6
2016-01-01	49.5
2016-04-01	49.2
2016-07-01	50.1
2016-10-01	51.1
2017-01-01	51.8
2017-04-01	51.5
2017-07-01	53.0
2017-10-01	51.5
2018-01-01	52.6
2018-04-01	51.8