Quarter	Percent
1999-04-01	45.7
1999-07-01	45.7
1999-10-01	46.1
2000-01-01	46.3
2000-04-01	46.3
2000-07-01	46.5
2000-10-01	47
2001-01-01	47.6
2001-04-01	47.9
2001-07-01	48.2
2001-10-01	48.5
2002-01-01	48.7
2002-04-01	49.2
2002-07-01	49.4
2002-10-01	49.8
2003-01-01	49.8
2003-04-01	50.4
2003-07-01	50.3
2003-10-01	50.4
2004-01-01	51.1
2004-04-01	50.7
2004-07-01	50.1
2004-10-01	51.3
2005-01-01	52.3
2005-04-01	53.2
2005-07-01	53.2
2005-10-01	53.6
2006-01-01	54.3
2006-04-01	54.7
2006-07-01	54.4
2006-10-01	54.3
2007-01-01	55
2007-04-01	55.4
2007-07-01	55.3
2007-10-01	55.3
2008-01-01	55.4
2008-04-01	55.7
2008-07-01	56.1
2008-10-01	55.7
2009-01-01	55.4
2009-04-01	55.1
2009-07-01	55.0
2009-10-01	53.8
2010-01-01	54.5
2010-04-01	55.5
2010-07-01	55.7
2010-10-01	54.7
2011-01-01	55.0
2011-04-01	55.9
2011-07-01	55.5
2011-10-01	55.5
2012-01-01	54.8
2012-04-01	55.2
2012-07-01	55.0
2012-10-01	55.6
2013-01-01	56.8
2013-04-01	57.1
2013-07-01	57.5
2013-10-01	58.8
2014-01-01	58.3
2014-04-01	58.2
2014-07-01	58.8
2014-10-01	58.9
2015-01-01	59.5
2015-04-01	60.3
2015-07-01	60.2
2015-10-01	61.1
2016-01-01	61.4
2016-04-01	61.2
2016-07-01	60.5
2016-10-01	61.3
2017-01-01	61.9
2017-04-01	62.3
2017-07-01	62.2
2017-10-01	62.4
2018-01-01	62.6
2018-04-01	63.4