Quarter	Percent
1999-01-01	45.3
1999-04-01	45.9
1999-07-01	46.3
1999-10-01	46.4
2000-01-01	45.9
2000-04-01	46.3
2000-07-01	46.9
2000-10-01	47.2
2001-01-01	46.1
2001-04-01	46.1
2001-07-01	46.5
2001-10-01	46.1
2002-01-01	45.8
2002-04-01	46.2
2002-07-01	46.4
2002-10-01	46.4
2003-01-01	46.1
2003-04-01	46.9
2003-07-01	47.2
2003-10-01	47.2
2004-01-01	46.6
2004-04-01	46.6
2004-07-01	46.7
2004-10-01	46.7
2005-01-01	46.2
2005-04-01	46.5
2005-07-01	46.9
2005-10-01	46.7
2006-01-01	46.4
2006-04-01	47
2006-07-01	47
2006-10-01	47
2007-01-01	46.4
2007-04-01	46.8
2007-07-01	46.8
2007-10-01	46.3
2008-01-01	45.6
2008-04-01	45.9
2008-07-01	46.5
2008-10-01	46
2009-01-01	44.7
2009-04-01	45
2009-07-01	44.9
2009-10-01	44.8
2010-01-01	44.1
2010-04-01	44.7
2010-07-01	45.2
2010-10-01	45
2011-01-01	44.2
2011-04-01	45.1
2011-07-01	45.6
2011-10-01	45.5
2012-01-01	44.8
2012-04-01	45.9
2012-07-01	46.7
2012-10-01	46.4
2013-01-01	45.4
2013-04-01	46.8
2013-07-01	47.5
2013-10-01	47.8
2014-01-01	48.7
2014-04-01	49.2
2014-07-01	50.1
2014-10-01	50.1
2015-01-01	49.9
2015-04-01	50.9
2015-07-01	51.7
2015-10-01	51.6
2016-01-01	51.7
2016-04-01	52.8
2016-07-01	53.3
2016-10-01	53.6
2017-01-01	53.2
2017-04-01	53.9
2017-07-01	54.3
2017-10-01	54.3
2018-01-01	54.2
2018-04-01	54.7