Quarter	Millions of US Dollars
1977-04-01	50
1982-04-01	-50
1982-10-01	24
1983-01-01	21
1984-04-01	64
1984-07-01	20
1984-10-01	41
1985-01-01	19
1985-04-01	40
1985-07-01	42
1986-10-01	30
1987-07-01	69
1987-10-01	2
1988-01-01	169
1989-07-01	53
1991-04-01	-108
1991-07-01	-37
1992-07-01	-80
1992-10-01	-36
1993-01-01	-88
1994-07-01	8
1994-10-01	-109
1995-01-01	-52
1995-04-01	-103
1995-07-01	14
1996-04-01	111
1996-07-01	-177
1996-10-01	186
1999-07-01	-105
1999-10-01	1037
2000-04-01	61
2001-01-01	923
2001-04-01	-57
2001-07-01	115
2001-10-01	356
2002-01-01	249
2002-04-01	19
2002-07-01	-309
2002-10-01	359
2003-01-01	-387
2003-04-01	379
2003-07-01	-219
2003-10-01	-29
2004-01-01	-87
2004-04-01	1078
2004-07-01	-159
2004-10-01	180
2005-01-01	1119
2005-04-01	-94
2005-07-01	-323
2005-10-01	340
2006-01-01	-584
2006-04-01	390
2006-07-01	-206
2006-10-01	2453
2007-01-01	-702
2007-04-01	775
2007-07-01	104
2007-10-01	395
2008-01-01	500
2008-04-01	-487
2008-07-01	204
2008-10-01	808
2009-01-01	141
2009-04-01	169
2009-07-01	-1
2009-10-01	238
2010-01-01	0
2010-04-01	-296
2010-07-01	491
2010-10-01	73
2011-01-01	-1534
2011-04-01	-1542
2011-07-01	-391
2011-10-01	325
2012-01-01	-169
2012-04-01	38
2012-07-01	36
2012-10-01	1322
2013-01-01	531
2013-04-01	-386
2013-07-01	-5
2013-10-01	-452
2014-01-01	63
2014-04-01	669
2014-07-01	662
2014-10-01	-262
2015-01-01	-866
2015-04-01	315
2015-07-01	564
2015-10-01	21
2016-01-01	406
2016-04-01	-168
2016-07-01	697
2016-10-01	-560
2017-01-01	-363
2017-04-01	1096
2017-07-01	-717
2017-10-01	398
2018-01-01	-402
2018-04-01	46