Quarter	Millions of US Dollars
1972-01-01	42
1972-07-01	20
1972-10-01	35
1973-07-01	38
1973-10-01	43
1974-07-01	2
1974-10-01	50
1975-01-01	92
1975-04-01	24
1975-07-01	25
1975-10-01	25
1976-10-01	98
1977-01-01	42
1977-04-01	117
1977-07-01	523
1977-10-01	356
1978-01-01	304
1978-04-01	169
1978-07-01	126
1978-10-01	177
1979-01-01	119
1979-07-01	188
1979-10-01	80
1980-01-01	21
1980-04-01	175
1980-07-01	55
1980-10-01	89
1981-04-01	402
1981-07-01	409
1981-10-01	446
1982-01-01	169
1982-04-01	109
1982-07-01	-94
1982-10-01	-22
1983-01-01	-30
1983-04-01	-27
1983-07-01	-47
1983-10-01	-137
1984-04-01	-37
1984-07-01	-153
1985-04-01	-23
1985-07-01	-35
1985-10-01	-303
1986-01-01	-3
1986-04-01	-134
1986-07-01	-25
1986-10-01	-290
1987-01-01	-183
1987-04-01	-112
1987-07-01	-179
1987-10-01	-285
1988-01-01	-29
1988-04-01	-316
1988-07-01	-497
1988-10-01	-338
1989-04-01	-117
1989-07-01	-148
1989-10-01	27
1990-01-01	949
1990-04-01	568
1990-07-01	288
1990-10-01	379
1991-01-01	228
1991-04-01	900
1991-07-01	607
1991-10-01	1381
1992-01-01	928
1992-04-01	972
1992-07-01	874
1992-10-01	1296
1993-01-01	513
1993-04-01	2622
1993-07-01	2021
1993-10-01	3599
1994-01-01	3496
1994-04-01	97
1994-07-01	299
1994-10-01	243
1995-01-01	-2212
1995-04-01	-24
1995-07-01	495
1995-10-01	1374
1996-01-01	1273
1996-04-01	3166
1996-07-01	1272
1996-10-01	3861
1997-01-01	1882
1997-04-01	4314
1997-07-01	5948
1997-10-01	9
1998-01-01	2631
1998-04-01	3038
1998-07-01	43
1998-10-01	-550
1999-01-01	-1170
1999-04-01	2989
1999-07-01	840
1999-10-01	-337
2000-01-01	1601
2000-04-01	898
2000-07-01	679
2000-10-01	-2650
2001-01-01	1112
2001-04-01	-483
2001-07-01	469
2001-10-01	76
2002-01-01	-2024
2002-04-01	-1628
2002-07-01	-2069
2002-10-01	-151
2003-01-01	-1716
2003-04-01	-1198
2003-07-01	81
2003-10-01	2242
2004-01-01	37
2004-04-01	-3502
2004-07-01	-2100
2004-10-01	-1304
2005-01-01	1261
2005-04-01	-222
2005-07-01	1003
2005-10-01	2173
2006-01-01	1940
2006-04-01	205
2006-07-01	1492
2006-10-01	2083
2007-01-01	592
2007-04-01	8820
2007-07-01	-1772
2007-10-01	2609
2008-01-01	-1289
2008-04-01	-1803
2008-07-01	-1059
2008-10-01	-3002
2009-01-01	523
2009-04-01	673
2009-07-01	8893
2009-10-01	10199
2010-01-01	9844
2010-04-01	6321
2010-07-01	5300
2010-10-01	5124
2011-01-01	8917
2011-04-01	9108
2011-07-01	4067
2011-10-01	11604
2012-01-01	8113
2012-04-01	5560
2012-07-01	12282
2012-10-01	6404
2013-01-01	8482
2013-04-01	9915
2013-07-01	11495
2013-10-01	15886
2014-01-01	3643
2014-04-01	11453
2014-07-01	12442
2014-10-01	7098
2015-01-01	4840
2015-04-01	14490
2015-07-01	2606
2015-10-01	-1380
2016-01-01	17844
2016-04-01	1839
2016-07-01	3865
2016-10-01	9794
2017-01-01	3831
2017-04-01	1139
2017-07-01	15706
2017-10-01	1211
2018-01-01	5637
2018-04-01	4045