Quarter	Percent
1983-01-01	18.5
1983-04-01	16.5
1983-07-01	19.8
1983-10-01	21.1
1984-01-01	19.8
1984-04-01	17.2
1984-07-01	19.4
1984-10-01	19.5
1985-01-01	17.2
1985-04-01	14.3
1985-07-01	16.3
1985-10-01	16.5
1986-01-01	15
1986-04-01	12.3
1986-07-01	14.8
1986-10-01	15.4
1987-01-01	13.9
1987-04-01	11.3
1987-07-01	13.8
1987-10-01	14.4
1988-01-01	13
1988-04-01	10.5
1988-07-01	13.5
1988-10-01	13.5
1989-01-01	11.9
1989-04-01	9.1
1989-07-01	11.9
1989-10-01	12.1
1990-01-01	10.6
1990-04-01	8.1
1990-07-01	11.3
1990-10-01	11.8
1991-01-01	10.8
1991-04-01	8.9
1991-07-01	12.1
1991-10-01	13.1
1992-01-01	12.2
1992-04-01	10.6
1992-07-01	14.5
1992-10-01	16.5
1993-01-01	17.3
1993-04-01	16.5
1993-07-01	21.3
1993-10-01	22.9
1994-01-01	22.2
1994-04-01	19.2
1994-07-01	22.2
1994-10-01	22.6
1995-01-01	21.1
1995-04-01	18.5
1995-07-01	21.2
1995-10-01	21.3
1996-01-01	19.3
1996-04-01	16.3
1996-07-01	19.2
1996-10-01	19.4
1997-01-01	18.1
1997-04-01	16.4
1997-07-01	19.5
1997-10-01	19.9
1998-01-01	18.6
1998-04-01	17
1998-07-01	21.8
1998-10-01	23.3
1999-01-01	21.0
1999-04-01	21.6
1999-07-01	17.9
1999-10-01	12.7
2000-01-01	15.5
2000-04-01	12.2
2000-07-01	17.3
2000-10-01	12.7
2001-01-01	14.1
2001-04-01	14.3
2001-07-01	16.8
2001-10-01	18.7
2002-01-01	16.8
2002-04-01	16
2002-07-01	18
2002-10-01	18
2003-01-01	21.6
2003-04-01	20.1
2003-07-01	22.9
2003-10-01	24
2004-01-01	20.3
2004-04-01	15.8
2004-07-01	23.2
2004-10-01	20.9
2005-01-01	19.8
2005-04-01	20.6
2005-07-01	21.1
2005-10-01	22.4
2006-01-01	20.5
2006-04-01	18.4
2006-07-01	17.6
2006-10-01	18.5
2007-01-01	17.3
2007-04-01	16.2
2007-07-01	18.5
2007-10-01	16.3
2008-01-01	16.8
2008-04-01	14.8
2008-07-01	21.4
2008-10-01	16.1
2009-01-01	19.6
2009-04-01	18.9
2009-07-01	24.3
2009-10-01	22.9
2010-01-01	24
2010-04-01	22.1
2010-07-01	22.1
2010-10-01	21.6
2011-01-01	19.4
2011-04-01	15.9
2011-07-01	21.8
2011-10-01	17.6
2012-01-01	19
2012-04-01	16.3
2012-07-01	22.5
2012-10-01	23.8
2013-01-01	24.6
2013-04-01	22.7
2013-07-01	25.2
2013-10-01	26.4
2014-01-01	26
2014-04-01	23.2
2014-07-01	22.7
2014-10-01	24
2015-01-01	20.7
2015-04-01	23.8
2015-07-01	23.0
2015-10-01	27.7
2016-01-01	20.6
2016-04-01	21.3
2016-07-01	22.3
2016-10-01	22.7
2017-01-01	23.6
2017-04-01	19.3
2017-07-01	20.8
2017-10-01	17.1
2018-01-01	18.5
2018-04-01	18.2
2018-07-01	19.1