Quarter	Percent
1998-01-01	49.3
1998-04-01	50
1998-07-01	50.2
1998-10-01	49.7
1999-01-01	49.8
1999-04-01	49.7
1999-07-01	49.6
1999-10-01	49
2000-01-01	49.2
2000-04-01	50
2000-07-01	50.2
2000-10-01	49.9
2001-01-01	49.5
2001-04-01	49.8
2001-07-01	49.9
2001-10-01	49.1
2002-01-01	49.3
2002-04-01	50.7
2002-07-01	51
2002-10-01	50.8
2003-01-01	50.9
2003-04-01	51.6
2003-07-01	51.8
2003-10-01	51.4
2004-01-01	51.1
2004-04-01	52
2004-07-01	52.1
2004-10-01	51.9
2005-01-01	51.8
2005-04-01	52.5
2005-07-01	52.5
2005-10-01	52.5
2006-01-01	52.8
2006-04-01	53.3
2006-07-01	53.8
2006-10-01	53.3
2007-01-01	53.1
2007-04-01	53.8
2007-07-01	54.1
2007-10-01	53.8
2008-01-01	53.7
2008-04-01	54.6
2008-07-01	54.7
2008-10-01	54.2
2009-01-01	53.7
2009-04-01	54.2
2009-07-01	54.3
2009-10-01	53.5
2010-01-01	52.8
2010-04-01	52.8
2010-07-01	52.5
2010-10-01	51.2
2011-01-01	49.9
2011-04-01	49.5
2011-07-01	48.5
2011-10-01	46.8
2012-01-01	45.6
2012-04-01	45.1
2012-07-01	44.4
2012-10-01	43.7
2013-01-01	42.7
2013-04-01	43.1
2013-07-01	43.1
2013-10-01	42.5
2014-01-01	42.6
2014-04-01	43.4
2014-07-01	44
2014-10-01	43.5
2015-01-01	43.2
2015-04-01	44.7
2015-07-01	45.3
2015-10-01	45.0
2016-01-01	44.7
2016-04-01	45.9
2016-07-01	46.4
2016-10-01	45.4
2017-01-01	45.5
2017-04-01	47.2
2017-07-01	47.7
2017-10-01	46.6
2018-01-01	46.5
2018-04-01	48.3