Quarter	Millions of US Dollars
1972-01-01	50
1972-04-01	35
1972-07-01	101
1972-10-01	16
1974-04-01	17
1974-07-01	105
1974-10-01	25
1975-01-01	209
1975-04-01	356
1975-10-01	38
1976-01-01	93
1976-04-01	283
1976-07-01	400
1976-10-01	280
1977-01-01	68
1977-04-01	86
1977-07-01	484
1977-10-01	356
1978-01-01	584
1978-04-01	250
1978-07-01	371
1978-10-01	261
1979-01-01	268
1979-04-01	111
1979-07-01	13
1979-10-01	154
1980-01-01	225
1980-04-01	-105
1980-07-01	103
1980-10-01	30
1981-01-01	90
1981-04-01	83
1981-07-01	82
1981-10-01	428
1982-01-01	58
1982-04-01	117
1982-07-01	830
1982-10-01	301
1983-01-01	180
1983-04-01	-35
1983-07-01	446
1983-10-01	655
1984-01-01	650
1984-04-01	542
1984-07-01	315
1984-10-01	796
1985-01-01	794
1985-04-01	1157
1985-07-01	1900
1985-10-01	1335
1986-01-01	2086
1986-04-01	1992
1986-07-01	1433
1986-10-01	1954
1987-01-01	896
1987-04-01	1605
1987-07-01	1614
1987-10-01	333
1988-01-01	973
1988-04-01	2035
1988-07-01	1724
1988-10-01	2573
1989-01-01	2686
1989-04-01	1375
1989-07-01	1540
1989-10-01	-356
1990-01-01	362
1990-04-01	693
1990-07-01	172
1990-10-01	-531
1991-01-01	236
1991-04-01	-152
1991-07-01	334
1991-10-01	-312
1992-01-01	-211
1992-04-01	-1747
1992-07-01	-1508
1992-10-01	-661
1993-01-01	-1562
1993-04-01	-925
1993-07-01	20171
1993-10-01	150
1994-01-01	2846
1994-04-01	-1664
1994-07-01	2349
1994-10-01	1674
1995-01-01	3331
1995-04-01	468
1995-07-01	4030
1995-10-01	1324
1996-01-01	2935
1996-04-01	3177
1996-07-01	6679
1996-10-01	2390
1997-01-01	4758
1997-04-01	2606
1997-07-01	2419
1997-10-01	-6039
1998-01-01	3651
1998-04-01	-891
1998-07-01	3893
1998-10-01	-2079
1999-01-01	6835
1999-04-01	-4129
1999-07-01	8340
1999-10-01	2327
2000-01-01	4723
2000-04-01	2537
2000-07-01	3922
2000-10-01	1925
2001-01-01	2148
2001-04-01	5533
2001-07-01	4536
2001-10-01	983
2002-01-01	3414
2002-04-01	7407
2002-07-01	4013
2002-10-01	4029
2003-01-01	6832
2003-04-01	10119
2003-07-01	8977
2003-10-01	17622
2004-01-01	19413
2004-04-01	9338
2004-07-01	21807
2004-10-01	8149
2005-01-01	8227
2005-04-01	15290
2005-07-01	854
2005-10-01	10434
2006-01-01	22306
2006-04-01	18201
2006-07-01	16016
2006-10-01	21837
2007-01-01	14688
2007-04-01	26544
2007-07-01	1795
2007-10-01	-8979
2008-01-01	41433
2008-04-01	6158
2008-07-01	-20597
2008-10-01	-27798
2009-01-01	-11464
2009-04-01	21093
2009-07-01	24316
2009-10-01	30148
2010-01-01	15033
2010-04-01	-3905
2010-07-01	15488
2010-10-01	5268
2011-01-01	-2385
2011-04-01	14843
2011-07-01	-7158
2011-10-01	-6318
2012-01-01	17355
2012-04-01	-527
2012-07-01	22654
2012-10-01	4853
2013-01-01	11347
2013-04-01	2758
2013-07-01	13164
2013-10-01	15326
2014-01-01	1294
2014-04-01	13020
2014-07-01	-4546
2014-10-01	968
2015-01-01	5346
2015-04-01	7082
2015-07-01	-16054
2015-10-01	11004
2016-01-01	11354
2016-04-01	12616
2016-07-01	7679
2016-10-01	-10702
2017-01-01	-2897
2017-04-01	-3598
2017-07-01	1544
2017-10-01	-3760
2018-01-01	18296
2018-04-01	5984