Quarter	Percent
1998-04-01	57.1
1999-04-01	56.9
2000-04-01	58.9
2001-01-01	52.8
2001-04-01	47.8
2001-07-01	45.5
2001-10-01	53.8
2002-01-01	55.1
2002-04-01	49.5
2002-07-01	47.3
2002-10-01	54.2
2003-01-01	56.8
2003-04-01	49.5
2003-07-01	48.3
2003-10-01	56.4
2004-01-01	57
2004-04-01	51.1
2004-07-01	48.4
2004-10-01	55.2
2005-01-01	56.3
2005-04-01	45.5
2005-07-01	47.2
2005-10-01	55.1
2006-01-01	55
2006-04-01	44.7
2006-07-01	45.3
2006-10-01	51.8
2007-01-01	50.9
2007-04-01	46.4
2007-07-01	44.1
2007-10-01	51.5
2008-01-01	51.5
2008-04-01	42.7
2008-07-01	43.6
2008-10-01	51.7
2009-01-01	52.8
2009-04-01	43.5
2009-07-01	46
2009-10-01	53.4
2010-01-01	53.7
2010-04-01	43.3
2010-07-01	44.2
2010-10-01	51
2011-01-01	50.9
2011-04-01	42.1
2011-07-01	43.4
2011-10-01	51
2012-01-01	52.8
2012-04-01	44.3
2012-07-01	44.6
2012-10-01	51.3
2013-01-01	50.3
2013-04-01	42.2
2013-07-01	42.6
2013-10-01	49.4
2014-01-01	48.9
2014-04-01	40.9
2014-07-01	41.9
2014-10-01	48.8
2015-01-01	49.0
2015-04-01	42.8
2015-07-01	43.1
2015-10-01	49.7
2016-01-01	48.4
2016-04-01	40.6
2016-07-01	44.3
2016-10-01	49.9
2017-01-01	49.1
2017-04-01	42.0
2017-07-01	42.7
2017-10-01	49.9
2018-01-01	49.7
2018-04-01	43.4