Quarter	Percent
1987-12-31	37.8
1988-03-31	39.9
1988-06-30	38.7
1988-09-30	36.5
1988-12-31	32.2
1989-03-31	28.5
1989-06-30	24.4
1989-09-30	16.2
1989-12-31	12.2
1990-03-31	11.4
1990-06-30	10.7
1990-09-30	10.1
1990-12-31	8.9
1991-03-31	7.4
1991-06-30	5.4
1991-09-30	5.8
1991-12-31	5.6
1992-03-31	5.8
1992-06-30	6.5
1992-09-30	7.1
1992-12-31	6.9
1993-03-31	8
1993-06-30	8.7
1993-09-30	9
1993-12-31	9.7
1994-03-31	9.3
1994-06-30	8.3
1994-09-30	7.1
1994-12-31	6.9
1995-03-31	6.4
1995-06-30	6.3
1995-09-30	6.5
1995-12-31	6.2
1996-03-31	5.8
1996-06-30	5.6
1996-09-30	4.5
1996-12-31	4.5
1997-03-31	5
1997-06-30	5.6
1997-09-30	6.1
1997-12-31	5.6
1998-03-31	4.8
1998-06-30	4.2
1998-09-30	4.4
1998-12-31	4.7
1999-03-31	4.9
1999-06-30	5.4
1999-09-30	6.2
1999-12-31	6.5
2000-03-31	7.4
2000-06-30	7.8
2000-09-30	6.3
2000-12-31	5.4
2001-03-31	4.8
2001-06-30	5
2001-09-30	6.5
2001-12-31	7.8
2002-03-31	8.9
2002-06-30	9.6
2002-09-30	10.7
2002-12-31	11.7
2003-03-31	10.3
2003-06-30	10
2003-09-30	10.5
2003-12-31	10.3
2004-03-31	11.2
2004-06-30	11
2004-09-30	9.2
2004-12-31	8.7
2005-03-31	6.8
2005-06-30	5.2
2005-09-30	5.9
2005-12-31	5.7
2006-03-31	4.7
2006-06-30	6.1
2006-09-30	5.6
2006-12-31	5
2007-03-31	6.4
2007-06-30	4.1
2007-09-30	3.3
2007-12-31	1.7
2008-03-31	3.8
2008-06-30	4.2
2008-09-30	-0.3
2008-12-31	-5
2009-03-31	-6.4
2009-06-30	-6
2009-09-30	-2.5
2009-12-31	4
2010-03-31	3.5
2010-06-30	3
2010-09-30	2.9
2010-12-31	1.4
2011-03-31	1.3
2011-06-30	1.2
2011-09-30	1.1
2011-12-31	1.1
2012-03-31	1.2
2012-06-30	1.2
2012-09-30	1.1
2012-12-31	1
2013-03-31	0.7
2013-06-30	0.8
2013-09-30	0.9
2013-12-31	1.3
2014-03-31	1.7
2014-06-30	2.2
2014-09-30	2.4
2014-12-31	2.4
2015-03-31	2.2
2015-06-30	2.2
2015-09-30	2.6
2015-12-31	3.1
2016-03-31	3.9
2016-06-30	3.8
2016-09-30	3.7
2016-12-31	3.6
2017-03-31	3.4
2017-06-30	3.8
2017-09-30	3.8
2017-12-31	3.7
2018-03-31	3.6
2018-06-30	3.5
2018-09-30	3.3
2018-12-31	3.3
2019-03-31	3.2
2019-06-30	3
2019-09-30	3.2
2019-12-31	3.4
2020-03-31	3.5
2020-06-30	2.8
2020-09-30	2.6
2020-12-31	3
2021-03-31	3.8
2021-06-30	5.3
2021-09-30	5.4
2021-12-31	4.7
2022-03-31	4.3
2022-06-30	3.6
2022-09-30	3.9
2022-12-31	4
2023-03-31	3
2023-06-30	1.8
2023-09-30	0.8
2023-12-31	0