Quarter	Millions of US Dollars
1971-01-01	40
1971-04-01	40
1972-01-01	96
1972-04-01	96
1972-07-01	24
1972-10-01	25
1973-01-01	74
1973-04-01	12
1974-01-01	82
1974-04-01	22
1974-07-01	56
1974-10-01	129
1975-01-01	450
1975-04-01	228
1975-07-01	267
1975-10-01	322
1976-01-01	542
1976-04-01	507
1976-07-01	304
1976-10-01	236
1977-01-01	200
1977-04-01	84
1977-07-01	42
1977-10-01	366
1978-01-01	202
1978-04-01	192
1978-07-01	-9
1978-10-01	79
1979-01-01	203
1979-04-01	332
1979-07-01	467
1979-10-01	374
1980-01-01	-137
1980-04-01	574
1980-07-01	141
1980-10-01	405
1981-01-01	593
1981-04-01	21
1981-07-01	45
1981-10-01	-145
1982-01-01	236
1982-04-01	679
1982-07-01	455
1982-10-01	881
1983-01-01	619
1983-04-01	171
1983-07-01	-45
1983-10-01	363
1984-01-01	543
1984-04-01	243
1984-07-01	424
1984-10-01	103
1985-01-01	441
1985-04-01	363
1985-07-01	220
1985-10-01	-350
1986-01-01	114
1986-04-01	826
1986-07-01	-219
1986-10-01	684
1987-01-01	214
1987-04-01	59
1987-07-01	-304
1987-10-01	-263
1988-01-01	431
1988-04-01	812
1988-07-01	1856
1988-10-01	84
1989-01-01	342
1989-04-01	1192
1989-07-01	451
1989-10-01	69
1990-01-01	-61
1990-04-01	234
1990-07-01	1070
1990-10-01	321
1991-01-01	483
1991-04-01	41
1991-07-01	398
1991-10-01	1112
1992-01-01	1691
1992-04-01	808
1992-07-01	-14
1992-10-01	2962
1993-01-01	1390
1993-04-01	406
1993-07-01	5431
1993-10-01	105
1994-01-01	468
1994-04-01	78
1994-07-01	120
1994-10-01	1912
1995-01-01	179
1995-04-01	-139
1995-07-01	407
1995-10-01	-5
1996-01-01	824
1996-04-01	446
1996-07-01	366
1996-10-01	-13
1997-01-01	1072
1997-04-01	1936
1997-07-01	309
1997-10-01	-1692
1998-01-01	1262
1998-04-01	2756
1998-07-01	1081
1998-10-01	3541
1999-01-01	5892
1999-04-01	6978
1999-07-01	5188
1999-10-01	971
2000-01-01	970
2000-04-01	7440
2000-07-01	10093
2000-10-01	7135
2001-01-01	25168
2001-04-01	5611
2001-07-01	8928
2001-10-01	11051
2002-01-01	-6882
2002-04-01	713
2002-07-01	2406
2002-10-01	3325
2003-01-01	3499
2003-04-01	7581
2003-07-01	-2564
2003-10-01	2140
2004-01-01	-8477
2004-04-01	4784
2004-07-01	1097
2004-10-01	1331
2005-01-01	-4459
2005-04-01	3908
2005-07-01	-3191
2005-10-01	7445
2006-01-01	140
2006-04-01	8315
2006-07-01	-1262
2006-10-01	9549
2007-01-01	2097
2007-04-01	11774
2007-07-01	1477
2007-10-01	-3311
2008-01-01	156
2008-04-01	19383
2008-07-01	-331
2008-10-01	180
2009-01-01	17310
2009-04-01	31495
2009-07-01	15516
2009-10-01	8137
2010-01-01	15229
2010-04-01	5466
2010-07-01	4082
2010-10-01	9885
2011-01-01	10771
2011-04-01	4687
2011-07-01	4828
2011-10-01	12639
2012-01-01	12371
2012-04-01	7555
2012-07-01	2554
2012-10-01	7545
2013-01-01	3877
2013-04-01	2921
2013-07-01	4313
2013-10-01	1692
2014-01-01	9187
2014-04-01	18804
2014-07-01	-559
2014-10-01	-1787
2015-01-01	-2998
2015-04-01	-8603
2015-07-01	-3582
2015-10-01	8313
2016-01-01	-5359
2016-04-01	7003
2016-07-01	-1790
2016-10-01	15199
2017-01-01	-6920
2017-04-01	5984
2017-07-01	642
2017-10-01	-961
2018-01-01	-2809
2018-04-01	438