Quarter	Percent
1999-01-01	60.9
1999-04-01	58.1
1999-07-01	52.2
1999-10-01	56.1
2000-01-01	60.9
2000-04-01	59.3
2000-07-01	54.7
2000-10-01	58.2
2001-01-01	61.5
2001-04-01	59.9
2001-07-01	56.2
2001-10-01	60.4
2002-01-01	58
2002-04-01	59.8
2002-07-01	57.9
2002-10-01	62.5
2003-01-01	61.6
2003-04-01	61.7
2003-07-01	59.5
2003-10-01	57.7
2004-01-01	57
2004-04-01	56.9
2004-07-01	50.9
2004-10-01	54.8
2005-01-01	54.8
2005-04-01	59.1
2005-07-01	52.2
2005-10-01	55.8
2006-01-01	58.3
2006-04-01	55.5
2006-07-01	50.7
2006-10-01	57.9
2007-01-01	55.1
2007-04-01	53.9
2007-07-01	47.1
2007-10-01	53.3
2008-01-01	56.1
2008-04-01	53.8
2008-07-01	45.5
2008-10-01	54
2009-01-01	58.9
2009-04-01	56.6
2009-07-01	48.8
2009-10-01	54.4
2010-01-01	56.1
2010-04-01	57.8
2010-07-01	53.1
2010-10-01	55.5
2011-01-01	59.7
2011-04-01	59.9
2011-07-01	53.7
2011-10-01	58.9
2012-01-01	64.1
2012-04-01	62.9
2012-07-01	59
2012-10-01	61.3
2013-01-01	65.1
2013-04-01	62.4
2013-07-01	60.1
2013-10-01	63.9
2014-01-01	65.9
2014-04-01	64.6
2014-07-01	61.5
2014-10-01	61.7
2015-01-01	63.5
2015-04-01	62.5
2015-07-01	57.7
2015-10-01	60.7
2016-01-01	64.2
2016-04-01	65.7
2016-07-01	60.5
2016-10-01	62.3
2017-01-01	60.6
2017-04-01	57.3
2017-07-01	51.7
2017-10-01	59.0
2018-01-01	59.6
2018-04-01	54.9