Quarter	Percent
1999-01-01	56.9
2000-01-01	54
2000-04-01	54.8
2000-07-01	55.6
2000-10-01	55.2
2001-01-01	53.4
2001-04-01	53.2
2001-07-01	53.5
2001-10-01	52.5
2002-01-01	50.6
2002-04-01	50.9
2002-07-01	51.3
2002-10-01	50.7
2003-01-01	49.4
2003-04-01	50.2
2003-07-01	51.1
2003-10-01	50.9
2004-01-01	49.7
2004-04-01	50.6
2004-07-01	51.5
2004-10-01	52.2
2005-01-01	51.3
2005-04-01	51.7
2005-07-01	53.3
2005-10-01	53.2
2006-01-01	52
2006-04-01	53.6
2006-07-01	55.3
2006-10-01	55.5
2007-01-01	54.9
2007-04-01	56.2
2007-07-01	56.9
2007-10-01	57.4
2008-01-01	57.5
2008-04-01	58.4
2008-07-01	59.4
2008-10-01	59.3
2009-01-01	58.1
2009-04-01	58.4
2009-07-01	59.2
2009-10-01	58.3
2010-01-01	56.6
2010-04-01	57.7
2010-07-01	58.6
2010-10-01	58.2
2011-01-01	57.2
2011-04-01	58.3
2011-07-01	59.1
2011-10-01	58.5
2012-01-01	57.3
2012-04-01	58.3
2012-07-01	58.9
2012-10-01	58.4
2013-01-01	57.1
2013-04-01	58.2
2013-07-01	58.9
2013-10-01	58.5
2014-01-01	57.6
2014-04-01	59.1
2014-07-01	60.3
2014-10-01	59.8
2015-01-01	58.8
2015-04-01	59.3
2015-07-01	60.6
2015-10-01	60.6
2016-01-01	60.0
2016-04-01	60.6
2016-07-01	61.3
2016-10-01	61.6
2017-01-01	61.3
2017-04-01	61.9
2017-07-01	62.7
2017-10-01	62.2
2018-01-01	61.8
2018-04-01	62.5