Quarter	Millions of US Dollars
1971-10-01	31
1972-01-01	82
1972-04-01	40
1972-07-01	20
1972-10-01	35
1973-01-01	61
1973-07-01	51
1973-10-01	66
1974-10-01	50
1975-01-01	95
1975-04-01	77
1975-07-01	24
1975-10-01	62
1976-01-01	62
1976-04-01	143
1976-07-01	91
1976-10-01	81
1977-01-01	120
1977-04-01	306
1977-07-01	470
1977-10-01	492
1978-01-01	463
1978-04-01	124
1978-07-01	100
1978-10-01	100
1979-07-01	173
1979-10-01	7
1980-01-01	-37
1980-04-01	161
1980-10-01	75
1981-01-01	75
1981-04-01	539
1981-07-01	335
1981-10-01	690
1982-01-01	529
1982-04-01	33
1982-07-01	91
1982-10-01	-87
1983-01-01	-198
1983-04-01	-96
1983-07-01	-67
1983-10-01	-160
1984-01-01	-44
1984-04-01	-74
1984-07-01	-153
1984-10-01	-25
1985-01-01	-61
1985-04-01	-39
1985-07-01	-134
1985-10-01	-296
1986-04-01	-151
1986-07-01	-110
1986-10-01	-221
1987-01-01	-171
1987-04-01	-159
1987-07-01	-31
1987-10-01	-305
1988-01-01	-241
1988-04-01	-353
1988-07-01	-563
1988-10-01	-397
1989-01-01	-151
1989-04-01	-17
1989-07-01	0
1989-10-01	31
1990-01-01	35412
1990-04-01	567
1990-07-01	495
1990-10-01	273
1991-01-01	324
1991-04-01	1000
1991-07-01	330
1991-10-01	460
1992-01-01	356
1992-04-01	46
1992-07-01	173
1992-10-01	1847
1993-01-01	608
1993-04-01	2001
1993-07-01	5341
1993-10-01	1367
1994-01-01	4791
1994-04-01	1545
1994-07-01	1157
1994-10-01	-1491
1995-01-01	-4404
1995-04-01	684
1995-07-01	2887
1995-10-01	387
1996-01-01	3205
1996-04-01	586
1996-07-01	6906
1996-10-01	-59
1997-01-01	2114
1997-04-01	3550
1997-07-01	-2897
1997-10-01	-438
1998-01-01	1805
1998-04-01	-1032
1998-07-01	327
1998-10-01	807
1999-01-01	1673
1999-04-01	4555
1999-07-01	1568
1999-10-01	1594
2000-01-01	3970
2000-04-01	-708
2000-07-01	1971
2000-10-01	-1464
2001-01-01	6528
2001-04-01	-3649
2001-07-01	-639
2001-10-01	-5533
2002-01-01	1457
2002-04-01	-5330
2002-07-01	-597
2002-10-01	1914
2003-01-01	-7227
2003-04-01	-1412
2003-07-01	-3090
2003-10-01	576
2004-01-01	2462
2004-04-01	990
2004-07-01	2792
2004-10-01	478
2005-01-01	3422
2005-04-01	-374
2005-07-01	1016
2005-10-01	1144
2006-01-01	759
2006-04-01	-1841
2006-07-01	-1234
2006-10-01	2688
2007-01-01	1346
2007-04-01	24
2007-07-01	-1808
2007-10-01	2872
2008-01-01	-2081
2008-04-01	845
2008-07-01	-602
2008-10-01	-2794
2009-01-01	-1884
2009-04-01	-215
2009-07-01	3822
2009-10-01	8401
2010-01-01	3792
2010-04-01	4297
2010-07-01	4259
2010-10-01	-2794
2011-01-01	2392
2011-04-01	5286
2011-07-01	6102
2011-10-01	4268
2012-01-01	7816
2012-04-01	3270
2012-07-01	7643
2012-10-01	6430
2013-01-01	3786
2013-04-01	3114
2013-07-01	10724
2013-10-01	10375
2014-01-01	6585
2014-04-01	9377
2014-07-01	3569
2014-10-01	5965
2015-01-01	7377
2015-04-01	10987
2015-07-01	249
2015-10-01	2529
2016-01-01	22236
2016-04-01	3506
2016-07-01	2121
2016-10-01	6031
2017-01-01	6166
2017-04-01	-4324
2017-07-01	12578
2017-10-01	-84
2018-01-01	6637
2018-04-01	4550