Quarter	Percent
1999-04-01	66.5
2000-01-01	63
2000-04-01	68.2
2000-07-01	69.3
2000-10-01	65
2001-01-01	61.3
2001-04-01	67.5
2001-07-01	65.9
2001-10-01	62.5
2002-01-01	61.6
2002-04-01	65.1
2002-07-01	66.3
2002-10-01	62.4
2003-01-01	58.9
2003-04-01	64.1
2003-07-01	63.9
2003-10-01	59.9
2004-01-01	57.4
2004-04-01	61.5
2004-07-01	64
2004-10-01	61.4
2005-01-01	56.2
2005-04-01	61.9
2005-07-01	63.9
2005-10-01	60.3
2006-01-01	55.5
2006-04-01	58.4
2006-07-01	59.3
2006-10-01	54.5
2007-01-01	54.9
2007-04-01	59.3
2007-07-01	59.5
2007-10-01	56.4
2008-01-01	59.9
2008-04-01	64.6
2008-07-01	63.5
2008-10-01	58.9
2009-01-01	55.7
2009-04-01	60.5
2009-07-01	57.5
2009-10-01	53.8
2010-01-01	55.2
2010-04-01	59.4
2010-07-01	56.5
2010-10-01	55.2
2011-01-01	52.4
2011-04-01	55.1
2011-07-01	56.5
2011-10-01	54.7
2012-01-01	55
2012-04-01	58.8
2012-07-01	56.8
2012-10-01	54.5
2013-01-01	55
2013-04-01	56.8
2013-07-01	57.8
2013-10-01	54.1
2014-01-01	52.1
2014-04-01	54.7
2014-07-01	53.8
2014-10-01	51.6
2015-01-01	53.3
2015-04-01	56.5
2015-07-01	57.9
2015-10-01	53.3
2016-01-01	53.7
2016-04-01	55.0
2016-07-01	55.3
2016-10-01	51.9
2017-01-01	52.2
2017-04-01	54.4
2017-07-01	55.2
2017-10-01	52.3
2018-01-01	52.1
2018-04-01	55.7