Quarter	Percent
1983-01-01	23.2
1983-04-01	21.1
1983-07-01	25.1
1983-10-01	26.2
1984-01-01	24.6
1984-04-01	22.0
1984-07-01	25.3
1984-10-01	25.4
1985-01-01	23.0
1985-04-01	20
1985-07-01	22.6
1985-10-01	22.6
1986-01-01	20.6
1986-04-01	17.7
1986-07-01	20.9
1986-10-01	21.8
1987-01-01	20.3
1987-04-01	17.5
1987-07-01	20.3
1987-10-01	20.4
1988-01-01	18.3
1988-04-01	15.3
1988-07-01	18.6
1988-10-01	18.2
1989-01-01	16.1
1989-04-01	13.1
1989-07-01	16.5
1989-10-01	16.5
1990-01-01	14.7
1990-04-01	12.1
1990-07-01	15.7
1990-10-01	15.7
1991-01-01	14
1991-04-01	11.7
1991-07-01	15.2
1991-10-01	15.6
1992-01-01	14.3
1992-04-01	12.5
1992-07-01	16.6
1992-10-01	18.1
1993-01-01	18.5
1993-04-01	17.6
1993-07-01	22.6
1993-10-01	23.9
1994-01-01	23.2
1994-04-01	20.6
1994-07-01	24.2
1994-10-01	24.5
1995-01-01	22.9
1995-04-01	20.4
1995-07-01	23.9
1995-10-01	24.1
1996-01-01	22.3
1996-04-01	19.5
1996-07-01	23.3
1996-10-01	23.4
1997-01-01	21.8
1997-04-01	19.8
1997-07-01	23.3
1997-10-01	23.2
1998-01-01	21.2
1998-04-01	19.0
1998-07-01	23.8
1998-10-01	24.3
1999-01-01	21.9
1999-04-01	21.6
1999-07-01	21.2
1999-10-01	16.7
2000-01-01	15.6
2000-04-01	14.5
2000-07-01	20.3
2000-10-01	16.1
2001-01-01	14.1
2001-04-01	15.3
2001-07-01	17.8
2001-10-01	19.6
2002-01-01	17.8
2002-04-01	15.7
2002-07-01	18.9
2002-10-01	18.4
2003-01-01	20.8
2003-04-01	19.0
2003-07-01	24.5
2003-10-01	22.6
2004-01-01	19.6
2004-04-01	17.5
2004-07-01	25.0
2004-10-01	22.3
2005-01-01	20.5
2005-04-01	19.9
2005-07-01	23.4
2005-10-01	22.1
2006-01-01	20.0
2006-04-01	18.9
2006-07-01	23.0
2006-10-01	20.0
2007-01-01	18.6
2007-04-01	19.2
2007-07-01	20.3
2007-10-01	17.4
2008-01-01	16.5
2008-04-01	14.3
2008-07-01	22.7
2008-10-01	17.8
2009-01-01	20.8
2009-04-01	19.8
2009-07-01	24.0
2009-10-01	23.0
2010-01-01	24.8
2010-04-01	21.1
2010-07-01	22.5
2010-10-01	21.2
2011-01-01	18.7
2011-04-01	16.4
2011-07-01	23
2011-10-01	16.6
2012-01-01	18.8
2012-04-01	16.2
2012-07-01	21.7
2012-10-01	22.0
2013-01-01	23.3
2013-04-01	22.5
2013-07-01	24.5
2013-10-01	24.4
2014-01-01	26.3
2014-04-01	23.4
2014-07-01	21.3
2014-10-01	22.2
2015-01-01	20.4
2015-04-01	20.4
2015-07-01	22.2
2015-10-01	25.4
2016-01-01	19.8
2016-04-01	19.2
2016-07-01	21.8
2016-10-01	19.7
2017-01-01	21.4
2017-04-01	19.9
2017-07-01	19.1
2017-10-01	16.8
2018-01-01	16.9
2018-04-01	18.0
2018-07-01	19.8