Quarter	Percent
1999-04-01	49.2
2000-04-01	49.6
2001-04-01	49.6
2002-04-01	50
2003-04-01	50.5
2004-04-01	52.5
2005-01-01	50.8
2005-04-01	51.3
2005-07-01	49.5
2005-10-01	49.8
2006-01-01	49.8
2006-04-01	50.5
2006-07-01	49.2
2006-10-01	48.7
2007-01-01	48.3
2007-04-01	50.2
2007-07-01	47.5
2007-10-01	47.7
2008-01-01	47.1
2008-04-01	48.8
2008-07-01	47.5
2008-10-01	47.9
2009-01-01	48.2
2009-04-01	49.1
2009-07-01	47.3
2009-10-01	48.3
2010-01-01	48.9
2010-04-01	50
2010-07-01	48.0
2010-10-01	48.0
2011-01-01	48.1
2011-04-01	48.4
2011-07-01	47
2011-10-01	46.9
2012-01-01	49.7
2012-04-01	50.2
2012-07-01	48.5
2012-10-01	48.8
2013-01-01	49
2013-04-01	50
2013-07-01	48.6
2013-10-01	49
2014-01-01	50.1
2014-04-01	51.4
2014-07-01	49.3
2014-10-01	49.5
2015-01-01	50.0
2015-04-01	52.9
2015-07-01	51.4
2015-10-01	50.4
2016-01-01	51.4
2016-04-01	52.5
2016-07-01	49.7
2016-10-01	49.5
2017-01-01	50.7
2017-04-01	51.6
2017-07-01	49.6
2017-10-01	48.7
2018-01-01	50.2
2018-04-01	51.0