Quarter	Percent
1998-04-01	49.8
1998-10-01	50.3
1999-04-01	50.4
1999-10-01	52.1
2000-04-01	55.2
2000-10-01	58.0
2001-04-01	56.6
2001-10-01	60.2
2002-01-01	58.4
2002-04-01	58.3
2002-07-01	52.9
2002-10-01	53.6
2003-01-01	56.8
2003-04-01	54.8
2003-07-01	55.9
2003-10-01	56.4
2004-01-01	56.8
2004-04-01	56.9
2004-07-01	54.9
2004-10-01	55.8
2005-01-01	55.1
2005-04-01	59.0
2005-07-01	54.1
2005-10-01	56.3
2006-01-01	53.5
2006-04-01	55.8
2006-07-01	48.5
2006-10-01	52.2
2007-01-01	51.7
2007-04-01	52.9
2007-07-01	47.4
2007-10-01	51.3
2008-01-01	50.1
2008-04-01	52.1
2008-07-01	48.8
2008-10-01	53.1
2009-01-01	52.5
2009-04-01	53.0
2009-07-01	52.4
2009-10-01	56.5
2010-01-01	54.2
2010-04-01	58.6
2010-07-01	56.8
2010-10-01	61.5
2011-01-01	59.7
2011-04-01	58.0
2011-07-01	57.9
2011-10-01	59.9
2012-01-01	58.2
2012-04-01	56.1
2012-07-01	52.5
2012-10-01	57.2
2013-01-01	56.9
2013-04-01	59.8
2013-07-01	56.8
2013-10-01	56.3
2014-01-01	55.7
2014-04-01	57.0
2014-07-01	51.9
2014-10-01	54.1
2015-01-01	58.2
2015-04-01	54.6
2015-07-01	54.5
2015-10-01	51.7
2016-01-01	57.6
2016-04-01	55.2
2016-07-01	53.9
2016-10-01	60.5
2017-01-01	60.3
2017-04-01	55.1
2017-07-01	53.8
2017-10-01	59.5
2018-01-01	62.6
2018-04-01	60.5