Quarter	Percent
1999-04-01	46.4
2000-01-01	44.9
2000-04-01	46.5
2000-07-01	46.2
2000-10-01	45.6
2001-01-01	45.2
2001-04-01	45.4
2001-07-01	47.7
2001-10-01	46.5
2002-01-01	45.3
2002-04-01	46.7
2002-07-01	47
2002-10-01	48.1
2003-01-01	47.4
2003-04-01	47
2003-07-01	48.2
2003-10-01	48.5
2004-01-01	48.7
2004-04-01	48.6
2004-07-01	47.9
2004-10-01	48
2005-01-01	49.4
2005-04-01	50.7
2005-07-01	49.4
2005-10-01	50.2
2006-01-01	51.2
2006-04-01	52.3
2006-07-01	51.6
2006-10-01	51.8
2007-01-01	51.4
2007-04-01	52.6
2007-07-01	52.5
2007-10-01	51.6
2008-01-01	51.4
2008-04-01	51.6
2008-07-01	52.6
2008-10-01	52.2
2009-01-01	50.4
2009-04-01	49
2009-07-01	48.5
2009-10-01	48.3
2010-01-01	47.6
2010-04-01	47.7
2010-07-01	46.6
2010-10-01	47.4
2011-01-01	47.6
2011-04-01	49.1
2011-07-01	50.6
2011-10-01	49.6
2012-01-01	50.1
2012-04-01	51.2
2012-07-01	50.6
2012-10-01	49.5
2013-01-01	50
2013-04-01	51.8
2013-07-01	51.1
2013-10-01	50.6
2014-01-01	49.1
2014-04-01	51.2
2014-07-01	52
2014-10-01	51.2
2015-01-01	51.4
2015-04-01	52.3
2015-07-01	53.6
2015-10-01	52.7
2016-01-01	52.1
2016-04-01	54.6
2016-07-01	53.1
2016-10-01	52.0
2017-01-01	53.1
2017-04-01	53.6
2017-07-01	54.6
2017-10-01	54.9
2018-01-01	53.6
2018-04-01	54.4