Quarter	Millions of US Dollars
1975-04-01	53
1975-07-01	25
1978-07-01	25
1979-01-01	48
1979-04-01	35
1980-07-01	81
1980-10-01	29
1981-04-01	30
1982-07-01	-25
1985-07-01	-35
1985-10-01	-1
1986-01-01	-25
1986-07-01	-73
1986-10-01	-58
1990-04-01	-53
1991-01-01	245
1992-01-01	40
1992-04-01	20
1993-01-01	35
1993-04-01	333
1993-10-01	95
1994-01-01	-101
1994-04-01	-15
1994-07-01	0
1994-10-01	5
1995-01-01	-75
1996-01-01	246
1996-04-01	340
1996-07-01	440
1997-01-01	84
1997-07-01	300
1997-10-01	650
1998-04-01	450
1998-10-01	213
1999-01-01	360
1999-04-01	800
1999-07-01	204
2000-01-01	100
2000-07-01	395
2001-04-01	220
2001-07-01	821
2001-10-01	650
2002-04-01	864
2002-07-01	262
2002-10-01	816
2003-01-01	928
2003-04-01	-101
2003-07-01	10
2003-10-01	-22
2004-01-01	443
2004-07-01	-253
2004-10-01	500
2005-04-01	150
2005-07-01	-61
2006-01-01	-617
2006-04-01	400
2006-07-01	-200
2006-10-01	500
2007-01-01	134
2007-04-01	270
2007-07-01	-687
2007-10-01	-185
2008-01-01	-609
2008-04-01	-65
2008-07-01	392
2009-01-01	591
2009-04-01	-840
2009-07-01	351
2009-10-01	1051
2010-01-01	490
2010-04-01	380
2010-07-01	2218
2010-10-01	1500
2011-01-01	1645
2011-04-01	226
2011-07-01	940
2011-10-01	1631
2012-01-01	50
2012-04-01	503
2012-07-01	2134
2012-10-01	2914
2013-01-01	1650
2013-04-01	2282
2013-07-01	2099
2013-10-01	3744
2014-01-01	679
2014-04-01	494
2014-07-01	5506
2014-10-01	4291
2015-01-01	1135
2015-04-01	3872
2015-07-01	2233
2015-10-01	59
2016-01-01	2507
2016-04-01	-357
2016-07-01	913
2016-10-01	336
2017-01-01	555
2017-04-01	4890
2017-07-01	6648
2017-10-01	526
2018-01-01	2491
2018-04-01	-18