Quarter	Percent
1999-04-01	40.7
2000-04-01	41.4
2001-04-01	42.4
2002-04-01	43.5
2003-01-01	43.7
2003-04-01	43.7
2003-07-01	43.7
2003-10-01	43.7
2004-01-01	45.4
2004-04-01	45.4
2004-07-01	45.4
2004-10-01	45.4
2005-01-01	46.3
2005-04-01	46.3
2005-07-01	46.3
2005-10-01	46.3
2006-01-01	49.4
2006-04-01	49.4
2006-07-01	49.4
2006-10-01	49.4
2007-01-01	50.4
2007-04-01	48.3
2007-07-01	50.8
2007-10-01	52
2008-01-01	48.1
2008-04-01	48.8
2008-07-01	47.8
2008-10-01	47.5
2009-01-01	50.6
2009-04-01	49.5
2009-07-01	49.7
2009-10-01	49.8
2010-01-01	49.8
2010-04-01	48.9
2010-07-01	50.2
2010-10-01	50.2
2011-01-01	51.2
2011-04-01	49.7
2011-07-01	50
2011-10-01	50.1
2012-01-01	50.9
2012-04-01	51.1
2012-07-01	53.4
2012-10-01	52.2
2013-01-01	52.3
2013-04-01	53
2013-07-01	51.9
2013-10-01	52.7
2014-01-01	53.3
2014-04-01	53
2014-07-01	53.2
2014-10-01	54.3
2015-01-01	55.4
2015-04-01	54.8
2015-07-01	54.2
2015-10-01	53.8
2016-01-01	53.1
2016-04-01	52.8
2016-07-01	54.0
2016-10-01	54.1
2017-01-01	54.8
2017-04-01	54.3
2017-07-01	56.3
2017-10-01	54.5
2018-01-01	56.1
2018-04-01	54.9