Quarter	Percent
1999-01-01	45.7
2000-01-01	41.1
2000-04-01	41.1
2000-07-01	40.6
2000-10-01	38.8
2001-01-01	38.3
2001-04-01	40.8
2001-07-01	40.2
2001-10-01	38.9
2002-01-01	38.4
2002-04-01	39.7
2002-07-01	38.9
2002-10-01	38
2003-01-01	38.3
2003-04-01	39.5
2003-07-01	40.5
2003-10-01	40.4
2004-01-01	38.3
2004-04-01	38.9
2004-07-01	39.2
2004-10-01	39.8
2005-01-01	39
2005-04-01	39.9
2005-07-01	42.4
2005-10-01	42.1
2006-01-01	40.6
2006-04-01	41.4
2006-07-01	43.8
2006-10-01	44.2
2007-01-01	43.3
2007-04-01	44.7
2007-07-01	45.1
2007-10-01	45.9
2008-01-01	46.1
2008-04-01	46.7
2008-07-01	46.9
2008-10-01	47.3
2009-01-01	46.8
2009-04-01	46.7
2009-07-01	48.8
2009-10-01	47.6
2010-01-01	48
2010-04-01	48
2010-07-01	49.5
2010-10-01	50.1
2011-01-01	50.4
2011-04-01	51.4
2011-07-01	52.4
2011-10-01	52.2
2012-01-01	51.9
2012-04-01	53.9
2012-07-01	54.2
2012-10-01	54.1
2013-01-01	54.7
2013-04-01	55.7
2013-07-01	56.5
2013-10-01	56.8
2014-01-01	55.8
2014-04-01	56.5
2014-07-01	58
2014-10-01	58.5
2015-01-01	56.9
2015-04-01	55.9
2015-07-01	58.3
2015-10-01	59.1
2016-01-01	58.2
2016-04-01	57.4
2016-07-01	58.6
2016-10-01	60.4
2017-01-01	59.9
2017-04-01	60.1
2017-07-01	61.4
2017-10-01	61.8
2018-01-01	60.2
2018-04-01	61.4