Quarter	Percent
1986-01-01	64.3
1986-04-01	63.9
1986-07-01	63.6
1986-10-01	63.9
1987-01-01	63.9
1987-04-01	63.4
1987-07-01	63.2
1987-10-01	63.6
1988-01-01	62.2
1988-04-01	61.3
1988-07-01	60.1
1988-10-01	60.7
1989-01-01	59.5
1989-04-01	58.6
1989-07-01	58.4
1989-10-01	59.3
1990-01-01	59
1990-04-01	59.1
1990-07-01	58.4
1990-10-01	58.6
1991-01-01	57.7
1991-04-01	57.2
1991-07-01	56.5
1991-10-01	56.8
1992-01-01	56.6
1992-04-01	56.8
1992-07-01	56.1
1992-10-01	56.9
1993-01-01	56.6
1993-04-01	56.8
1993-07-01	57
1993-10-01	58
1994-01-01	57.9
1994-04-01	58.4
1994-07-01	58.7
1994-10-01	60
1995-01-01	60
1995-04-01	60.3
1995-07-01	60.5
1995-10-01	61.4
1996-01-01	61.2
1996-04-01	61.4
1996-07-01	61.6
1996-10-01	61.7
1997-01-01	61.1
1997-04-01	61
1997-07-01	60.7
1997-10-01	61.2
1998-01-01	60.4
1998-04-01	59.8
1998-07-01	59.7
1998-10-01	60.1
1999-01-01	60.3
1999-04-01	60.0
1999-07-01	60.3
1999-10-01	61.6
2000-01-01	60.9
2000-04-01	60.4
2000-07-01	61.2
2000-10-01	62.3
2001-01-01	61.8
2001-04-01	61.8
2001-07-01	62
2001-10-01	63.2
2002-01-01	63.2
2002-04-01	62.8
2002-07-01	62.6
2002-10-01	63.4
2003-01-01	62.8
2003-04-01	62.6
2003-07-01	63.3
2003-10-01	63.9
2004-01-01	63.6
2004-04-01	63.4
2004-07-01	64.1
2004-10-01	65.7
2005-01-01	64.8
2005-04-01	64.5
2005-07-01	65.2
2005-10-01	65.8
2006-01-01	65.6
2006-04-01	65.6
2006-07-01	65.2
2006-10-01	65.8
2007-01-01	65.8
2007-04-01	65.8
2007-07-01	65.5
2007-10-01	66.6
2008-01-01	64.9
2008-04-01	65.5
2008-07-01	65.4
2008-10-01	66.4
2009-01-01	64.6
2009-04-01	64.2
2009-07-01	63.3
2009-10-01	63.9
2010-01-01	63.5
2010-04-01	63.2
2010-07-01	63.5
2010-10-01	63.9
2011-01-01	63.9
2011-04-01	63.7
2011-07-01	63.6
2011-10-01	64.3
2012-01-01	63.9
2012-04-01	63.5
2012-07-01	63.0
2012-10-01	62.8
2013-01-01	63.5
2013-04-01	63.3
2013-07-01	63.9
2013-10-01	64.9
2014-01-01	64.9
2014-04-01	64.5
2014-07-01	64.6
2014-10-01	65.9
2015-01-01	65.7
2015-04-01	65.0
2015-07-01	64.1
2015-10-01	65.3
2016-01-01	65.4
2016-04-01	66.1
2016-07-01	66.2
2016-10-01	67.2
2017-01-01	67.3
2017-04-01	66.5
2017-07-01	67.4
2017-10-01	68.2
2018-01-01	67.9
2018-04-01	67.5
2018-07-01	67.9