Quarter	Percent
1999-01-01	42.1
2000-01-01	43.1
2001-01-01	43.7
2002-01-01	44.3
2003-01-01	45.7
2003-04-01	45.8
2003-07-01	46
2003-10-01	45.2
2004-01-01	45.2
2004-04-01	45.7
2004-07-01	46.1
2004-10-01	45.5
2005-01-01	45.7
2005-04-01	46.1
2005-07-01	46
2005-10-01	45.3
2006-01-01	45.4
2006-04-01	45.8
2006-07-01	46.2
2006-10-01	46.3
2007-01-01	46.1
2007-04-01	46.7
2007-07-01	47.2
2007-10-01	47
2008-01-01	47.2
2008-04-01	47.4
2008-07-01	47.6
2008-10-01	47
2009-01-01	46.8
2009-04-01	47.2
2009-07-01	47.2
2009-10-01	46.5
2010-01-01	46.7
2010-04-01	47.0
2010-07-01	47.1
2010-10-01	46.3
2011-01-01	46.3
2011-04-01	46.8
2011-07-01	46.9
2011-10-01	46.6
2012-01-01	46.5
2012-04-01	46.9
2012-07-01	46.9
2012-10-01	46.5
2013-01-01	46.3
2013-04-01	46.8
2013-07-01	47
2013-10-01	46.6
2014-01-01	46.4
2014-04-01	46.7
2014-07-01	46.5
2014-10-01	46.2
2015-01-01	46.2
2015-04-01	46.6
2015-07-01	46.8
2015-10-01	46.4
2016-01-01	46.4
2016-04-01	46.7
2016-07-01	46.7
2016-10-01	46.3
2017-01-01	46.1
2017-04-01	46.9
2017-07-01	46.6
2017-10-01	46.8
2018-01-01	46.6
2018-04-01	47.1