Quarter	Percent
1999-04-01	59.5
2000-01-01	55.6
2000-04-01	47.6
2000-07-01	57.7
2000-10-01	49.9
2001-01-01	48.5
2001-04-01	53
2001-07-01	55.6
2001-10-01	53.7
2002-01-01	55.7
2002-04-01	52.7
2002-07-01	51.5
2002-10-01	53.2
2003-01-01	53
2003-04-01	53.4
2003-07-01	52.1
2003-10-01	61.2
2004-01-01	54.7
2004-04-01	49.6
2004-07-01	53
2004-10-01	58.7
2005-01-01	55.4
2005-04-01	56.7
2005-07-01	55.3
2005-10-01	58.7
2006-01-01	61.3
2006-04-01	59.2
2006-07-01	55.3
2006-10-01	53.2
2007-01-01	56.5
2007-04-01	59.8
2007-07-01	58
2007-10-01	61.6
2008-01-01	64.7
2008-04-01	62.8
2008-07-01	64.5
2008-10-01	66.9
2009-01-01	63.3
2009-04-01	61.6
2009-07-01	56
2009-10-01	56.2
2010-01-01	49.6
2010-04-01	47.4
2010-07-01	51.8
2010-10-01	58.9
2011-01-01	55.1
2011-04-01	53
2011-07-01	60
2011-10-01	60.5
2012-01-01	56
2012-04-01	56.6
2012-07-01	60.6
2012-10-01	63.4
2013-01-01	60.8
2013-04-01	62
2013-07-01	61.7
2013-10-01	61.2
2014-01-01	59.8
2014-04-01	65.3
2014-07-01	67.2
2014-10-01	68.3
2015-01-01	62.8
2015-04-01	59.6
2015-07-01	64.9
2015-10-01	65.0
2016-01-01	60.4
2016-04-01	67.0
2016-07-01	67.1
2016-10-01	60.5
2017-01-01	66.1
2017-04-01	68.7
2017-07-01	66.2
2017-10-01	65.3
2018-01-01	61.9
2018-04-01	63.5