Quarter	Percent
2000-04-01	73.4
2001-04-01	73.1
2002-04-01	71.8
2003-04-01	69.8
2004-04-01	68.7
2005-01-01	66.4
2005-04-01	65.7
2005-07-01	65.9
2005-10-01	65.2
2006-01-01	64.7
2006-04-01	64.3
2006-07-01	64.3
2006-10-01	63.7
2007-01-01	63.4
2007-04-01	62.3
2007-07-01	62.9
2007-10-01	62.4
2008-01-01	62.6
2008-04-01	61.6
2008-07-01	61.6
2008-10-01	61.2
2009-01-01	60.6
2009-04-01	59.6
2009-07-01	60.2
2009-10-01	59.7
2010-01-01	59.2
2010-04-01	59.1
2010-07-01	58.9
2010-10-01	58.6
2011-01-01	57.9
2011-04-01	57.0
2011-07-01	56.8
2011-10-01	56.4
2012-01-01	55.7
2012-04-01	54.7
2012-07-01	54.3
2012-10-01	54.1
2013-01-01	53.5
2013-04-01	53.0
2013-07-01	52.3
2013-10-01	51.9
2014-01-01	51.5
2014-04-01	50.6
2014-07-01	50.3
2014-10-01	49.8
2015-01-01	49.5
2015-04-01	48.8
2015-07-01	48.8
2015-10-01	48.4
2016-01-01	47.6
2016-04-01	46.8
2016-07-01	46.8
2016-10-01	46.4
2017-01-01	45.8
2017-04-01	45.1
2017-07-01	45.2
2017-10-01	44.5
2018-01-01	44.1
2018-04-01	43.8