Quarter	Percent
1999-01-01	57
1999-04-01	57.9
1999-07-01	58.7
1999-10-01	58.5
2000-01-01	58.6
2000-04-01	59.4
2000-07-01	60.1
2000-10-01	60
2001-01-01	59.8
2001-04-01	60.5
2001-07-01	61
2001-10-01	60.7
2002-01-01	60.3
2002-04-01	60.8
2002-07-01	61
2002-10-01	60.6
2003-01-01	60.7
2003-04-01	61.3
2003-07-01	61.7
2003-10-01	61.4
2004-01-01	61.2
2004-04-01	61.6
2004-07-01	62.1
2004-10-01	62.2
2005-01-01	62.4
2005-04-01	63.1
2005-07-01	63.9
2005-10-01	63.6
2006-01-01	63.5
2006-04-01	64
2006-07-01	64.6
2006-10-01	64.1
2007-01-01	63.9
2007-04-01	64.4
2007-07-01	64.6
2007-10-01	63.7
2008-01-01	63.2
2008-04-01	62.6
2008-07-01	61.9
2008-10-01	59.5
2009-01-01	56.8
2009-04-01	56.1
2009-07-01	55.7
2009-10-01	54.8
2010-01-01	53.9
2010-04-01	54.4
2010-07-01	54.6
2010-10-01	53.7
2011-01-01	53
2011-04-01	53.2
2011-07-01	53
2011-10-01	51.8
2012-01-01	50.4
2012-04-01	50.3
2012-07-01	50.2
2012-10-01	49.2
2013-01-01	48.3
2013-04-01	48.8
2013-07-01	49.2
2013-10-01	48.9
2014-01-01	48.3
2014-04-01	49.7
2014-07-01	50.5
2014-10-01	50.3
2015-01-01	50.1
2015-04-01	51.4
2015-07-01	52.1
2015-10-01	51.9
2016-01-01	51.9
2016-04-01	52.5
2016-07-01	53.2
2016-10-01	52.9
2017-01-01	52.8
2017-04-01	53.9
2017-07-01	54.7
2017-10-01	54.2
2018-01-01	53.8
2018-04-01	55.0
2018-07-01	55.6