Quarter	Percent
1986-01-01	3.8
1986-04-01	3.6
1986-07-01	3.6
1986-10-01	3.7
1987-01-01	3.8
1987-04-01	4.0
1987-07-01	4.1
1987-10-01	4.3
1988-01-01	5.1
1988-04-01	5.4
1988-07-01	6.4
1988-10-01	6.5
1989-01-01	7.4
1989-04-01	7.7
1989-07-01	7.6
1989-10-01	7.1
1990-01-01	7.6
1990-04-01	8.3
1990-07-01	8.4
1990-10-01	9.2
1991-01-01	10.4
1991-04-01	10.8
1991-07-01	11.9
1991-10-01	12.0
1992-01-01	11.9
1992-04-01	11.1
1992-07-01	11.4
1992-10-01	11.1
1993-01-01	11.2
1993-04-01	10.6
1993-07-01	10.1
1993-10-01	10
1994-01-01	9.9
1994-04-01	9.0
1994-07-01	8.4
1994-10-01	7.9
1995-01-01	7.1
1995-04-01	6.2
1995-07-01	6.3
1995-10-01	6.2
1996-01-01	6.6
1996-04-01	5.9
1996-07-01	6.3
1996-10-01	6.4
1997-01-01	6.7
1997-04-01	6.8
1997-07-01	6.9
1997-10-01	7.1
1998-01-01	7.6
1998-04-01	7.8
1998-07-01	8.0
1998-10-01	7.9
1999-01-01	8.2
1999-04-01	7.5
1999-07-01	7.2
1999-10-01	6.4
2000-01-01	6.7
2000-04-01	6.2
2000-07-01	6.2
2000-10-01	5.9
2001-01-01	5.7
2001-04-01	5.5
2001-07-01	5.2
2001-10-01	5.5
2002-01-01	5.5
2002-04-01	4.9
2002-07-01	5.4
2002-10-01	4.8
2003-01-01	5.0
2003-04-01	4.4
2003-07-01	4.1
2003-10-01	4.2
2004-01-01	3.9
2004-04-01	3.6
2004-07-01	3.5
2004-10-01	3.3
2005-01-01	4.0
2005-04-01	3.7
2005-07-01	3.3
2005-10-01	3.1
2006-01-01	4.0
2006-04-01	3.2
2006-07-01	3.5
2006-10-01	3.4
2007-01-01	3.9
2007-04-01	3.1
2007-07-01	3.2
2007-10-01	3.2
2008-01-01	3.9
2008-04-01	3.7
2008-07-01	4.0
2008-10-01	4.1
2009-01-01	5.4
2009-04-01	5.3
2009-07-01	6.2
2009-10-01	6.4
2010-01-01	5.9
2010-04-01	6.4
2010-07-01	5.4
2010-10-01	5.8
2011-01-01	6.0
2011-04-01	5.7
2011-07-01	5.5
2011-10-01	6.0
2012-01-01	6.3
2012-04-01	5.8
2012-07-01	6.5
2012-10-01	6.0
2013-01-01	5.3
2013-04-01	5.3
2013-07-01	5.3
2013-10-01	5.0
2014-01-01	5.2
2014-04-01	4.4
2014-07-01	4.5
2014-10-01	4.8
2015-01-01	5.2
2015-04-01	4.6
2015-07-01	5.1
2015-10-01	4.7
2016-01-01	5.1
2016-04-01	4.5
2016-07-01	4.7
2016-10-01	4.8
2017-01-01	4.4
2017-04-01	4.5
2017-07-01	4.0
2017-10-01	4.0
2018-01-01	4.1
2018-04-01	4.2
2018-07-01	3.8