Quarter	Percent
1999-04-01	46.1
2000-04-01	46.3
2001-04-01	46.6
2002-04-01	47.2
2003-04-01	47.8
2004-04-01	49.5
2005-01-01	48.1
2005-04-01	48.5
2005-07-01	46.3
2005-10-01	47.4
2006-01-01	46.7
2006-04-01	47.8
2006-07-01	46.7
2006-10-01	46.2
2007-01-01	45.6
2007-04-01	48.3
2007-07-01	44.5
2007-10-01	45.6
2008-01-01	44.5
2008-04-01	46.7
2008-07-01	44.5
2008-10-01	45.4
2009-01-01	45.5
2009-04-01	47.2
2009-07-01	43.7
2009-10-01	46.4
2010-01-01	46.2
2010-04-01	47.7
2010-07-01	45.5
2010-10-01	45.7
2011-01-01	45.4
2011-04-01	46.4
2011-07-01	45.1
2011-10-01	44
2012-01-01	46.7
2012-04-01	48.1
2012-07-01	46
2012-10-01	46.3
2013-01-01	47
2013-04-01	47.9
2013-07-01	46.1
2013-10-01	47.5
2014-01-01	48
2014-04-01	49.8
2014-07-01	46.9
2014-10-01	47.2
2015-01-01	48.3
2015-04-01	51.8
2015-07-01	49.7
2015-10-01	48.4
2016-01-01	49.7
2016-04-01	51.1
2016-07-01	48.1
2016-10-01	47.4
2017-01-01	49.1
2017-04-01	50.2
2017-07-01	48.2
2017-10-01	47.4
2018-01-01	48.3
2018-04-01	48.4