Quarter	Percent of Capacity, Seasonally Adjusted
1968-10-01	81.3
1969-01-01	81.1
1969-04-01	84.2
1969-07-01	82.7
1969-10-01	75.5
1970-01-01	81.2
1970-04-01	81.5
1970-07-01	80.4
1970-10-01	78.9
1971-01-01	78
1971-04-01	76.9
1971-07-01	76.4
1971-10-01	76.6
1972-01-01	75
1972-04-01	77.2
1972-07-01	77.3
1972-10-01	76.4
1973-01-01	73.7
1973-04-01	78.8
1973-07-01	78.5
1973-10-01	78.8
1974-01-01	78.2
1974-04-01	78.3
1974-07-01	77.2
1974-10-01	73.1
1975-01-01	70.4
1975-04-01	70.6
1975-07-01	68.3
1975-10-01	68
1976-01-01	71.7
1976-04-01	73.9
1976-07-01	74.8
1976-10-01	75.6
1977-01-01	75.1
1977-04-01	73.1
1977-07-01	71.6
1977-10-01	71.5
1978-01-01	72.9
1978-04-01	73.6
1978-07-01	73.5
1978-10-01	75.4
1979-01-01	76.4
1979-04-01	75.2
1979-07-01	75.9
1979-10-01	77.6
1980-01-01	77.7
1980-04-01	76.6
1980-07-01	70.8
1980-10-01	73
1981-01-01	72.3
1981-04-01	73.3
1981-07-01	72.7
1981-10-01	72.1
1982-01-01	72.3
1982-04-01	72.6
1982-07-01	70.6
1982-10-01	70.3
1983-01-01	70.6
1983-04-01	70.6
1983-07-01	70.8
1983-10-01	70.5
1984-01-01	71.7
1984-04-01	73.3
1984-07-01	73.3
1984-10-01	74.3
1985-01-01	73.2
1985-04-01	73.8
1985-07-01	73.2
1985-10-01	73.2
1986-01-01	73.4
1986-04-01	74.8
1986-07-01	74.6
1986-10-01	74.4
1987-01-01	75.4
1987-04-01	76.3
1987-07-01	77.1
1987-10-01	76.1
1988-01-01	77.1
1988-04-01	75.6
1988-07-01	77.3
1988-10-01	78.6
1989-01-01	79.4
1989-04-01	78.7
1989-07-01	79.5
1989-10-01	80.4
1990-01-01	79.8
1990-04-01	79.7
1990-07-01	79.5
1990-10-01	78.6
1991-01-01	75.3
1991-04-01	75.7
1991-07-01	73.6
1991-10-01	74.5
1992-01-01	74.7
1992-04-01	75
1992-07-01	72.3
1992-10-01	73.3
1993-01-01	73.4
1993-04-01	72.5
1993-07-01	71.1
1993-10-01	72.2
1994-01-01	72.9
1994-04-01	73.9
1994-07-01	74.6
1994-10-01	76.4
1995-01-01	77.9
1995-04-01	78.2
1995-07-01	79.4
1995-10-01	78.6
1996-01-01	76
1996-04-01	75.1
1996-07-01	74.6
1996-10-01	74.6
1997-01-01	74.1
1997-04-01	75.8
1997-07-01	76.6
1997-10-01	77.2
1998-01-01	77.1
1998-04-01	76.9
1998-07-01	76.7
1998-10-01	75.6
1999-01-01	74.9
1999-04-01	74.8
1999-07-01	76.1
1999-10-01	75.9
2000-01-01	78
2000-04-01	78.2
2000-07-01	77.9
2000-10-01	78.6
2001-01-01	78.5
2001-04-01	77.5
2001-07-01	76.5
2001-10-01	75.2
2002-01-01	75.3
2002-04-01	75.3
2002-07-01	76.6
2002-10-01	75.4
2003-01-01	75.8
2003-04-01	74.8
2003-07-01	76.7
2003-10-01	75.5
2004-01-01	76.2
2004-04-01	75.8
2004-07-01	76.0
2004-10-01	76.4
2005-01-01	76.2
2005-04-01	75.3
2005-07-01	74.9
2005-10-01	75.8
2006-01-01	76.2
2006-04-01	76.8
2006-07-01	77.6
2006-10-01	77.3
2007-01-01	77.3
2007-04-01	78.4
2007-07-01	78.1
2007-10-01	77.6
2008-01-01	76.8
2008-04-01	76
2008-07-01	76.1
2008-10-01	75.3
2009-01-01	70.1
2009-04-01	65.5
2009-07-01	64.2
2009-10-01	64.4
2010-01-01	66.4
2010-04-01	68.9
2010-07-01	70.6
2010-10-01	72.5
2011-01-01	74.7
2011-04-01	76.4
2011-07-01	73.7
2011-10-01	73.3
2012-01-01	72.4
2012-04-01	72.9
2012-07-01	71.1
2012-10-01	70.9
2013-01-01	70
2013-04-01	69.8
2013-07-01	72.7
2013-10-01	73.8
2014-01-01	73.6
2014-04-01	73.5
2014-07-01	73.6
2014-10-01	73.9
2015-01-01	74.6
2015-04-01	76.1
2015-07-01	75.5
2015-10-01	75.9
2016-01-01	77.1
2016-04-01	76.5
2016-07-01	76.0
2016-10-01	75.7
2017-01-01	76.5
2017-04-01	76.0
2017-07-01	77.0
2017-10-01	77.6
2018-01-01	78.3
2018-04-01	78.1
2018-07-01	77.9
2018-10-01	77.9