Quarter	Percent
1988-03-31	30.7
1988-06-30	29.1
1988-09-30	29.8
1988-12-31	26.8
1989-03-31	26.2
1989-06-30	25.9
1989-09-30	23
1989-12-31	22.2
1990-03-31	18
1990-06-30	14.6
1990-09-30	11.2
1990-12-31	8.6
1991-03-31	8.4
1991-06-30	6.5
1991-09-30	5.1
1991-12-31	4.5
1992-03-31	2.6
1992-06-30	0.6
1992-09-30	1
1992-12-31	1
1993-03-31	1.4
1993-06-30	3.3
1993-09-30	4.3
1993-12-31	5.5
1994-03-31	6.9
1994-06-30	8.5
1994-09-30	9.5
1994-12-31	10.9
1995-03-31	12.1
1995-06-30	12
1995-09-30	12.8
1995-12-31	13.6
1996-03-31	13.6
1996-06-30	14.6
1996-09-30	16.2
1996-12-31	16.2
1997-03-31	16.7
1997-06-30	17.5
1997-09-30	14.5
1997-12-31	14.8
1998-03-31	15.7
1998-06-30	14.7
1998-09-30	15.8
1998-12-31	14.7
1999-03-31	13.9
1999-06-30	13.8
1999-09-30	13.3
1999-12-31	13.2
2000-03-31	13.2
2000-06-30	12.4
2000-09-30	10.9
2000-12-31	10.5
2001-03-31	10.1
2001-06-30	11.2
2001-09-30	12.6
2001-12-31	14.1
2002-03-31	14.9
2002-06-30	14.6
2002-09-30	15.3
2002-12-31	14.9
2003-03-31	14
2003-06-30	13.6
2003-09-30	12.4
2003-12-31	11.4
2004-03-31	11.8
2004-06-30	11.9
2004-09-30	11.9
2004-12-31	11.8
2005-03-31	11.5
2005-06-30	11.1
2005-09-30	10.4
2005-12-31	9.5
2006-03-31	8.3
2006-06-30	7.5
2006-09-30	7.2
2006-12-31	7.4
2007-03-31	7
2007-06-30	7.2
2007-09-30	7.3
2007-12-31	7.2
2008-03-31	7.6
2008-06-30	7
2008-09-30	5.4
2008-12-31	4.1
2009-03-31	1.9
2009-06-30	0.9
2009-09-30	-0.7
2009-12-31	-1.7
2010-03-31	-1.3