Quarter	Percent
1999-04-01	67
2000-01-01	66.1
2000-04-01	66.9
2000-07-01	67
2000-10-01	66.4
2001-01-01	66.1
2001-04-01	67
2001-07-01	66.9
2001-10-01	67.1
2002-01-01	66.9
2002-04-01	67.6
2002-07-01	67.3
2002-10-01	66.6
2003-01-01	65.9
2003-04-01	66.4
2003-07-01	66.8
2003-10-01	66.1
2004-01-01	65.3
2004-04-01	66.4
2004-07-01	66.4
2004-10-01	66
2005-01-01	65.1
2005-04-01	65.4
2005-07-01	66.2
2005-10-01	65.8
2006-01-01	65.2
2006-04-01	65.9
2006-07-01	66.4
2006-10-01	66.5
2007-01-01	66.7
2007-04-01	67.6
2007-07-01	68
2007-10-01	68.6
2008-01-01	68.8
2008-04-01	69.1
2008-07-01	69.1
2008-10-01	68.7
2009-01-01	68.5
2009-04-01	68.3
2009-07-01	67.6
2009-10-01	67.3
2010-01-01	66.6
2010-04-01	67
2010-07-01	66.5
2010-10-01	66.4
2011-01-01	66.5
2011-04-01	66.7
2011-07-01	66.6
2011-10-01	66.4
2012-01-01	66.5
2012-04-01	67.3
2012-07-01	66.7
2012-10-01	66.1
2013-01-01	65.8
2013-04-01	66.2
2013-07-01	66.3
2013-10-01	66.1
2014-01-01	60.5
2014-04-01	60.8
2014-07-01	60.6
2014-10-01	61.2
2015-01-01	59.2
2015-04-01	60.5
2015-07-01	60.0
2015-10-01	59.3
2016-01-01	59.7
2016-04-01	59.4
2016-07-01	60.2
2016-10-01	59.2
2017-01-01	58.9
2017-04-01	59.4
2017-07-01	59.4
2017-10-01	58.9
2018-01-01	58.9
2018-04-01	59.5