Quarter	Percent
1999-04-01	59.3
2000-04-01	58.6
2001-04-01	57.6
2002-04-01	56.5
2003-01-01	56.3
2003-04-01	56.3
2003-07-01	56.3
2003-10-01	56.3
2004-01-01	54.6
2004-04-01	54.6
2004-07-01	54.6
2004-10-01	54.6
2005-01-01	53.7
2005-04-01	53.7
2005-07-01	53.7
2005-10-01	53.7
2006-01-01	50.6
2006-04-01	50.6
2006-07-01	50.6
2006-10-01	50.6
2007-01-01	49.6
2007-04-01	51.7
2007-07-01	49.2
2007-10-01	48
2008-01-01	51.9
2008-04-01	51.2
2008-07-01	52.2
2008-10-01	52.5
2009-01-01	49.4
2009-04-01	50.5
2009-07-01	50.3
2009-10-01	50.2
2010-01-01	50.2
2010-04-01	51.1
2010-07-01	49.8
2010-10-01	49.8
2011-01-01	48.8
2011-04-01	50.3
2011-07-01	50
2011-10-01	49.9
2012-01-01	49.1
2012-04-01	48.9
2012-07-01	46.6
2012-10-01	47.8
2013-01-01	47.7
2013-04-01	47
2013-07-01	48.1
2013-10-01	47.3
2014-01-01	46.7
2014-04-01	47
2014-07-01	46.8
2014-10-01	45.7
2015-01-01	44.6
2015-04-01	45.2
2015-07-01	45.8
2015-10-01	46.2
2016-01-01	46.9
2016-04-01	47.2
2016-07-01	46.0
2016-10-01	45.9
2017-01-01	45.2
2017-04-01	45.7
2017-07-01	43.7
2017-10-01	45.5
2018-01-01	43.9
2018-04-01	45.1