Quarter	Percent
1987-12-31	44.9
1988-03-31	55.6
1988-06-30	56.5
1988-09-30	58.4
1988-12-31	59.8
1989-03-31	55.8
1989-06-30	59.8
1989-09-30	54.7
1989-12-31	48.1
1990-03-31	43.9
1990-06-30	33.1
1990-09-30	26.3
1990-12-31	23.6
1991-03-31	18.4
1991-06-30	13.7
1991-09-30	8.6
1991-12-31	2.3
1992-03-31	-1.7
1992-06-30	-3.4
1992-09-30	-4.2
1992-12-31	-3.9
1993-03-31	-5.6
1993-06-30	-6
1993-09-30	-7.3
1993-12-31	-9
1994-03-31	-8.2
1994-06-30	-9.7
1994-09-30	-8.1
1994-12-31	-5.3
1995-03-31	-3.9
1995-06-30	-0.1
1995-09-30	0.9
1995-12-31	-3.5
1996-03-31	-2.2
1996-06-30	-4.6
1996-09-30	-4.8
1996-12-31	0.9
1997-03-31	-2.8
1997-06-30	4.4
1997-09-30	-0.9
1997-12-31	-4.4
1998-03-31	2.3
1998-06-30	-0.9
1998-09-30	9.4
1998-12-31	14.7
1999-03-31	17
1999-06-30	13.4
1999-09-30	11.9
1999-12-31	15.4
2000-03-31	13.9
2000-06-30	18.4
2000-09-30	22.2
2000-12-31	24
2001-03-31	24.3
2001-06-30	24.2
2001-09-30	24.5
2001-12-31	22.4
2002-03-31	21.5
2002-06-30	21.1
2002-09-30	20.3
2002-12-31	20
2003-03-31	21.8
2003-06-30	23.2
2003-09-30	20.3
2003-12-31	16.5
2004-03-31	15.5
2004-06-30	17
2004-09-30	16.6
2004-12-31	16.5
2005-03-31	18.6
2005-06-30	18.7
2005-09-30	20
2005-12-31	21.2
2006-03-31	19.1
2006-06-30	18.1
2006-09-30	18
2006-12-31	18.4
2007-03-31	17.3
2007-06-30	18.2
2007-09-30	20.4
2007-12-31	21.3
2008-03-31	22.5
2008-06-30	19.6
2008-09-30	16
2008-12-31	11.9
2009-03-31	7.7
2009-06-30	4.3
2009-09-30	0.8
2009-12-31	-0.2
2010-03-31	-1.2
2010-06-30	-1.9
2010-09-30	-2.8
2010-12-31	-3.2
2011-03-31	-2.9
2011-06-30	-1.6
2011-09-30	-0.5
2011-12-31	-0.5
2012-03-31	-2.8
2012-06-30	-4
2012-09-30	-4.8
2012-12-31	-5.3
2013-03-31	-4.4
2013-06-30	-4.8
2013-09-30	-5.5
2013-12-31	-7.1
2014-03-31	-8
2014-06-30	-7.8
2014-09-30	-7.2
2014-12-31	-5.7
2015-03-31	-4.3
2015-06-30	-3.8
2015-09-30	-2.2
2015-12-31	-1.1
2016-03-31	1.4
2016-06-30	2.7
2016-09-30	2.5
2016-12-31	2.9
2017-03-31	0.7
2017-06-30	-0.1
2017-09-30	-2
2017-12-31	-1.9
2018-03-31	-1.6
2018-06-30	-1.7
2018-09-30	2.3
2018-12-31	3.2
2019-03-31	4
2019-06-30	6.2
2019-09-30	5.2
2019-12-31	4.8
2020-03-31	7.1
2020-06-30	6.3
2020-09-30	4.2
2020-12-31	2.7
2021-03-31	0.7
2021-06-30	-0.8
2021-09-30	-1.2
2021-12-31	0.5
2022-03-31	0.4
2022-06-30	2.2
2022-09-30	3.3
2022-12-31	4
2023-03-31	3.6
2023-06-30	3.6
2023-09-30	4.5
2023-12-31	5.1