Quarter	Percent
1999-04-01	43.7
1999-07-01	44
1999-10-01	44.4
2000-01-01	45
2000-04-01	45.1
2000-07-01	45.3
2000-10-01	45.8
2001-01-01	46.2
2001-04-01	46.6
2001-07-01	47
2001-10-01	47.4
2002-01-01	47.4
2002-04-01	48
2002-07-01	48.3
2002-10-01	48.4
2003-01-01	48.5
2003-04-01	49.2
2003-07-01	49.1
2003-10-01	49.1
2004-01-01	49.7
2004-04-01	49.5
2004-07-01	48.8
2004-10-01	50
2005-01-01	50.7
2005-04-01	51.7
2005-07-01	51.8
2005-10-01	52.2
2006-01-01	53.1
2006-04-01	53.4
2006-07-01	52.9
2006-10-01	53.1
2007-01-01	53.5
2007-04-01	54.1
2007-07-01	54
2007-10-01	54.0
2008-01-01	53.8
2008-04-01	53.9
2008-07-01	54.0
2008-10-01	53.5
2009-01-01	52.1
2009-04-01	51.9
2009-07-01	51.1
2009-10-01	49.9
2010-01-01	50.0
2010-04-01	50.8
2010-07-01	50.8
2010-10-01	49.5
2011-01-01	50.1
2011-04-01	50.8
2011-07-01	49.8
2011-10-01	49.8
2012-01-01	49.1
2012-04-01	49.7
2012-07-01	48.9
2012-10-01	49.8
2013-01-01	50.2
2013-04-01	50.8
2013-07-01	51.3
2013-10-01	52.9
2014-01-01	52.4
2014-04-01	52.5
2014-07-01	53.4
2014-10-01	53.6
2015-01-01	54.5
2015-04-01	55.5
2015-07-01	55.8
2015-10-01	56.8
2016-01-01	57.2
2016-04-01	57.1
2016-07-01	56.9
2016-10-01	57.6
2017-01-01	58.0
2017-04-01	58.9
2017-07-01	58.8
2017-10-01	58.9
2018-01-01	59.4
2018-04-01	60.5