Quarter	Percent
1998-01-01	56.5
1998-04-01	55.5
1998-07-01	55.1
1998-10-01	54.6
1999-01-01	55.1
1999-04-01	54.4
1999-07-01	54.3
1999-10-01	54.2
2000-01-01	54.7
2000-04-01	53.8
2000-07-01	53.3
2000-10-01	53
2001-01-01	53.2
2001-04-01	52.9
2001-07-01	52.5
2001-10-01	52.3
2002-01-01	52.6
2002-04-01	52
2002-07-01	51.9
2002-10-01	51.9
2003-01-01	52.2
2003-04-01	51.3
2003-07-01	51.4
2003-10-01	51.7
2004-01-01	49.3
2004-04-01	49.4
2004-07-01	49.5
2004-10-01	48.6
2005-01-01	49.5
2005-04-01	49.6
2005-07-01	50.3
2005-10-01	48.7
2006-01-01	49.1
2006-04-01	49
2006-07-01	49.9
2006-10-01	48.8
2007-01-01	50.1
2007-04-01	49.5
2007-07-01	49.3
2007-10-01	48.5
2008-01-01	48.4
2008-04-01	47.9
2008-07-01	48.7
2008-10-01	48.4
2009-01-01	48.8
2009-04-01	48.5
2009-07-01	49.6
2009-10-01	48.6
2010-01-01	48.9
2010-04-01	48.6
2010-07-01	49.8
2010-10-01	48.4
2011-01-01	48.6
2011-04-01	48.7
2011-07-01	49.4
2011-10-01	47.5
2012-01-01	46.7
2012-04-01	46.3
2012-07-01	47.3
2012-10-01	46
2013-01-01	46
2013-04-01	46.5
2013-07-01	47.4
2013-10-01	45.8
2014-01-01	45.6
2014-04-01	45.9
2014-07-01	46.3
2014-10-01	44.6
2015-01-01	45.6
2015-04-01	45.6
2015-07-01	46.9
2015-10-01	45.5
2016-01-01	45.6
2016-04-01	44.3
2016-07-01	45.2
2016-10-01	44.1
2017-01-01	44.2
2017-04-01	44.0
2017-07-01	44.3
2017-10-01	43.7
2018-01-01	43.8
2018-04-01	43.0