Quarter	Percent
1986-01-01	80.1
1986-04-01	79.7
1986-07-01	79.2
1986-10-01	78.8
1987-01-01	78.7
1987-04-01	78.7
1987-07-01	78.4
1987-10-01	77.8
1988-01-01	77
1988-04-01	76.2
1988-07-01	75.8
1988-10-01	75.6
1989-01-01	75.4
1989-04-01	75
1989-07-01	74.6
1989-10-01	74.4
1990-01-01	74.3
1990-04-01	74.3
1990-07-01	74.4
1990-10-01	74.2
1991-01-01	74.1
1991-04-01	74
1991-07-01	73.9
1991-10-01	73.8
1992-01-01	73.7
1992-04-01	73.4
1992-07-01	73
1992-10-01	72.8
1993-01-01	73.0
1993-04-01	73.2
1993-07-01	73.3
1993-10-01	73.4
1994-01-01	73.5
1994-04-01	73.6
1994-07-01	73.8
1994-10-01	73.8
1995-01-01	73.9
1995-04-01	74
1995-07-01	74.2
1995-10-01	74.4
1996-01-01	74.4
1996-04-01	74.5
1996-07-01	74.6
1996-10-01	74.5
1997-01-01	74.3
1997-04-01	74.4
1997-07-01	74.4
1997-10-01	74.2
1998-01-01	74.1
1998-04-01	73.8
1998-07-01	73.4
1998-10-01	73.2
1999-01-01	73.3
1999-04-01	73.4
1999-07-01	73.4
1999-10-01	73.5
2000-01-01	73.4
2000-04-01	73.4
2000-07-01	73.6
2000-10-01	73.8
2001-01-01	73.6
2001-04-01	73.6
2001-07-01	73.9
2001-10-01	74.4
2002-01-01	74.8
2002-04-01	74.7
2002-07-01	74.4
2002-10-01	74.1
2003-01-01	73.8
2003-04-01	73.8
2003-07-01	73.7
2003-10-01	73.7
2004-01-01	73.8
2004-04-01	74.2
2004-07-01	74.7
2004-10-01	74.9
2005-01-01	75.0
2005-04-01	74.9
2005-07-01	75
2005-10-01	75.3
2006-01-01	75.4
2006-04-01	75.5
2006-07-01	75.5
2006-10-01	75.6
2007-01-01	75.6
2007-04-01	75.6
2007-07-01	75.5
2007-10-01	75.4
2008-01-01	75.3
2008-04-01	75.1
2008-07-01	75.2
2008-10-01	75.2
2009-01-01	75.1
2009-04-01	74.6
2009-07-01	74.3
2009-10-01	74.0
2010-01-01	74.0
2010-04-01	74.2
2010-07-01	74.3
2010-10-01	74.1
2011-01-01	74.1
2011-04-01	74.3
2011-07-01	74.2
2011-10-01	74.3
2012-01-01	74.2
2012-04-01	73.9
2012-07-01	73.6
2012-10-01	73.2
2013-01-01	72.9
2013-04-01	73.2
2013-07-01	73.8
2013-10-01	74.2
2014-01-01	74.3
2014-04-01	74.2
2014-07-01	74.2
2014-10-01	74.6
2015-01-01	74.9
2015-04-01	74.5
2015-07-01	74.0
2015-10-01	73.8
2016-01-01	74.3
2016-04-01	75.1
2016-07-01	75.8
2016-10-01	76.1
2017-01-01	76.1
2017-04-01	76.2
2017-07-01	76.3
2017-10-01	76.3
2018-01-01	76.2
2018-04-01	76.1
2018-07-01	76.1