Quarter	Percent of Capacity, Seasonally Adjusted
1974-04-01	11
1974-07-01	0
1974-10-01	-13
1975-01-01	-29
1975-04-01	-34
1975-07-01	-31
1975-10-01	-29
1976-01-01	-28
1976-04-01	-22
1976-07-01	-17
1976-10-01	-14
1977-01-01	-18
1977-04-01	-18
1977-07-01	-21
1977-10-01	-21
1978-01-01	-24
1978-04-01	-21
1978-07-01	-16
1978-10-01	-14
1979-01-01	-11
1979-04-01	-6
1979-07-01	-3
1979-10-01	-1
1980-01-01	1
1980-04-01	5
1980-07-01	1
1980-10-01	-3
1981-01-01	-6
1981-04-01	-8
1981-07-01	-7
1981-10-01	-7
1982-01-01	-8
1982-04-01	-12
1982-07-01	-15
1982-10-01	-17
1983-01-01	-20
1983-04-01	-17
1983-07-01	-15
1983-10-01	-10
1984-01-01	-7
1984-04-01	-3
1984-07-01	-2
1984-10-01	-2
1985-01-01	-3
1985-04-01	-2
1985-07-01	-5
1985-10-01	-8
1986-01-01	-11
1986-04-01	-12
1986-07-01	-15
1986-10-01	-18
1987-01-01	-19
1987-04-01	-17
1987-07-01	-13
1987-10-01	-6
1988-01-01	-3
1988-04-01	3
1988-07-01	4
1988-10-01	7
1989-01-01	8
1989-04-01	10
1989-07-01	9
1989-10-01	10
1990-01-01	10
1990-04-01	11
1990-07-01	13
1990-10-01	13
1991-01-01	13
1991-04-01	10
1991-07-01	8
1991-10-01	4
1992-01-01	-3
1992-04-01	-8
1992-07-01	-12
1992-10-01	-17
1993-01-01	-21
1993-04-01	-22
1993-07-01	-23
1993-10-01	-26
1994-01-01	-29
1994-04-01	-26
1994-07-01	-23
1994-10-01	-21
1995-01-01	-20
1995-04-01	-17
1995-07-01	-19
1995-10-01	-20
1996-01-01	-17
1996-04-01	-17
1996-07-01	-15
1996-10-01	-13
1997-01-01	-8
1997-04-01	-9
1997-07-01	-8
1997-10-01	-10
1998-01-01	-16
1998-04-01	-23
1998-07-01	-28
1998-10-01	-29
1999-01-01	-30
1999-04-01	-29
1999-07-01	-26
1999-10-01	-23
2000-01-01	-19
2000-04-01	-18
2000-07-01	-15
2000-10-01	-15
2001-01-01	-19
2001-04-01	-24
2001-07-01	-29
2001-10-01	-30
2002-01-01	-31
2002-04-01	-27
2002-07-01	-25
2002-10-01	-23
2003-01-01	-20
2003-04-01	-20
2003-07-01	-19
2003-10-01	-14
2004-01-01	-8
2004-04-01	-5
2004-07-01	-4
2004-10-01	-3
2005-01-01	-4
2005-04-01	-2
2005-07-01	-3
2005-10-01	-1
2006-01-01	0
2006-04-01	0
2006-07-01	1
2006-10-01	2
2007-01-01	1
2007-04-01	0
2007-07-01	0
2007-10-01	0
2008-01-01	0
2008-04-01	-2
2008-07-01	-6
2008-10-01	-14
2009-01-01	-36
2009-04-01	-36
2009-07-01	-34
2009-10-01	-30
2010-01-01	-25
2010-04-01	-19
2010-07-01	-14
2010-10-01	-14
2011-01-01	-12
2011-04-01	-13
2011-07-01	-10
2011-10-01	-10
2012-01-01	-11
2012-04-01	-11
2012-07-01	-12
2012-10-01	-14
2013-01-01	-14
2013-04-01	-12
2013-07-01	-10
2013-10-01	-8
2014-01-01	-5
2014-04-01	-5
2014-07-01	-4
2014-10-01	-3
2015-01-01	-2
2015-04-01	-3
2015-07-01	-3
2015-10-01	-3
2016-01-01	-4
2016-04-01	-4
2016-07-01	-3
2016-10-01	-2
2017-01-01	0
2017-04-01	0
2017-07-01	2
2017-10-01	4
2018-01-01	5
2018-04-01	6
2018-07-01	6