Quarter	Percent
1999-01-01	59.1
2000-01-01	56.1
2000-04-01	56.9
2000-07-01	57.5
2000-10-01	57
2001-01-01	55.2
2001-04-01	55.1
2001-07-01	55.6
2001-10-01	54.4
2002-01-01	52.5
2002-04-01	52.9
2002-07-01	53.4
2002-10-01	52.7
2003-01-01	51.3
2003-04-01	52.3
2003-07-01	53.2
2003-10-01	53
2004-01-01	51.8
2004-04-01	52.7
2004-07-01	53.7
2004-10-01	54.4
2005-01-01	53.6
2005-04-01	54.1
2005-07-01	55.8
2005-10-01	55.7
2006-01-01	54.4
2006-04-01	56.1
2006-07-01	57.9
2006-10-01	58
2007-01-01	57.5
2007-04-01	59.1
2007-07-01	59.8
2007-10-01	60.2
2008-01-01	60.5
2008-04-01	61.4
2008-07-01	62.6
2008-10-01	62.5
2009-01-01	61.2
2009-04-01	61.6
2009-07-01	62.5
2009-10-01	61.4
2010-01-01	59.5
2010-04-01	60.8
2010-07-01	61.8
2010-10-01	61.4
2011-01-01	60.3
2011-04-01	61.5
2011-07-01	62.3
2011-10-01	61.7
2012-01-01	60.5
2012-04-01	61.6
2012-07-01	62.2
2012-10-01	61.9
2013-01-01	60.5
2013-04-01	61.5
2013-07-01	62.4
2013-10-01	62.1
2014-01-01	61.1
2014-04-01	62.5
2014-07-01	63.9
2014-10-01	63.5
2015-01-01	62.4
2015-04-01	62.9
2015-07-01	64.3
2015-10-01	64.4
2016-01-01	63.8
2016-04-01	64.5
2016-07-01	65.2
2016-10-01	65.5
2017-01-01	65.2
2017-04-01	65.8
2017-07-01	66.7
2017-10-01	66.3
2018-01-01	65.9
2018-04-01	66.6