Quarter	Percent
1987-12-31	34.8
1988-03-31	39.2
1988-06-30	40.3
1988-09-30	37.9
1988-12-31	36.8
1989-03-31	31.5
1989-06-30	29.7
1989-09-30	26
1989-12-31	20.2
1990-03-31	20
1990-06-30	23.4
1990-09-30	20.9
1990-12-31	18.9
1991-03-31	16.2
1991-06-30	11.9
1991-09-30	4.6
1991-12-31	1.3
1992-03-31	-6
1992-06-30	-7
1992-09-30	-5.8
1992-12-31	-7.3
1993-03-31	-1.5
1993-06-30	-4.9
1993-09-30	-5
1993-12-31	0.5
1994-03-31	-4.1
1994-06-30	3.2
1994-09-30	1.1
1994-12-31	3.6
1995-03-31	3.8
1995-06-30	0.5
1995-09-30	7.3
1995-12-31	5.9
1996-03-31	3.6
1996-06-30	5
1996-09-30	4.5
1996-12-31	6.3
1997-03-31	16.9
1997-06-30	11.4
1997-09-30	7
1997-12-31	6.3
1998-03-31	6.3
1998-06-30	7.7
1998-09-30	12.9
1998-12-31	4.7
1999-03-31	2.6
1999-06-30	4.4
1999-09-30	0.9
1999-12-31	7.5
2000-03-31	5.1
2000-06-30	5.9
2000-09-30	14.7
2000-12-31	15.8
2001-03-31	20.4
2001-06-30	21.6
2001-09-30	11.5
2001-12-31	6.1
2002-03-31	3.6
2002-06-30	4
2002-09-30	10.6
2002-12-31	16.1
2003-03-31	17.3
2003-06-30	16.1
2003-09-30	9.8
2003-12-31	10.7
2004-03-31	3.9
2004-06-30	10.4
2004-09-30	15.9
2004-12-31	14.6
2005-03-31	14.1
2005-06-30	10.6
2005-09-30	7.9
2005-12-31	6.9
2006-03-31	18.6
2006-06-30	21.2
2006-09-30	23.8
2006-12-31	25.1
2007-03-31	33.5
2007-06-30	27.4
2007-09-30	34.3
2007-12-31	26.4
2008-03-31	17
2008-06-30	25
2008-09-30	27.7
2008-12-31	39.8
2009-03-31	40.2
2009-06-30	29.7
2009-09-30	17.5
2009-12-31	6.5
2010-03-31	-6.3
2010-06-30	-7.5
2010-09-30	-4.7
2010-12-31	-1.1
2011-03-31	3.3
2011-06-30	3
2011-09-30	-7.2
2011-12-31	-14.6
2012-03-31	-12.1
2012-06-30	-13.4
2012-09-30	-8.2
2012-12-31	3.4
2013-03-31	0.9
2013-06-30	2.7
2013-09-30	1.6
2013-12-31	-10.1
2014-03-31	-23.8
2014-06-30	-35.5
2014-09-30	-36
2014-12-31	-34.1
2015-03-31	-15.9
2015-06-30	-2.4
2015-09-30	0
2015-12-31	2
2016-03-31	-5.7
2016-06-30	-10.6
2016-09-30	-13
2016-12-31	-15.5
2017-03-31	-15.1
2017-06-30	-7.1
2017-09-30	-5.7
2017-12-31	2
2018-03-31	13.4
2018-06-30	19
2018-09-30	19.2
2018-12-31	15.7
2019-03-31	15.4
2019-06-30	12.2
2019-09-30	10.6
2019-12-31	13.3
2020-03-31	5.5
2020-06-30	-1.7
2020-09-30	-1.9
2020-12-31	-1
2021-03-31	-2.8
2021-06-30	3.5
2021-09-30	5.8
2021-12-31	-1
2022-03-31	7.7
2022-06-30	6.6
2022-09-30	7.3
2022-12-31	10.4
2023-03-31	4.3
2023-06-30	4.8
2023-09-30	3.2
2023-12-31	6.2