Quarter	Millions of US Dollars
1974-10-01	19
1976-04-01	10
1976-07-01	24
1976-10-01	40
1977-01-01	25
1977-10-01	46
1978-01-01	42
1978-04-01	14
1979-01-01	44
1979-07-01	-25
1980-10-01	47
1981-07-01	73
1981-10-01	-41
1982-01-01	16
1983-04-01	6
1983-07-01	70
1983-10-01	72
1984-01-01	44
1984-04-01	115
1984-07-01	190
1984-10-01	362
1985-01-01	100
1985-04-01	427
1985-07-01	343
1985-10-01	450
1986-01-01	359
1986-04-01	204
1986-07-01	20
1986-10-01	125
1987-01-01	25
1987-04-01	26
1987-07-01	205
1987-10-01	50
1988-01-01	-428
1988-04-01	-45
1988-07-01	80
1988-10-01	60
1989-01-01	-110
1989-04-01	-95
1989-07-01	-36
1989-10-01	166
1990-01-01	248
1990-04-01	-224
1990-07-01	58
1990-10-01	-133
1991-01-01	656
1991-04-01	1287
1991-07-01	270
1991-10-01	512
1992-01-01	706
1992-04-01	244
1992-07-01	1090
1992-10-01	901
1993-01-01	649
1993-04-01	777
1993-07-01	780
1993-10-01	2439
1994-01-01	833
1994-04-01	1533
1994-07-01	1310
1994-10-01	268
1995-01-01	1536
1995-04-01	2730
1995-07-01	2114
1995-10-01	1373
1996-01-01	2267
1996-04-01	3844
1996-07-01	5503
1996-10-01	5347
1997-01-01	2957
1997-04-01	2352
1997-07-01	4350
1997-10-01	115
1998-01-01	-906
1998-04-01	3908
1998-07-01	-1412
1998-10-01	-748
1999-01-01	-877
1999-04-01	-1356
1999-07-01	-1662
1999-10-01	455
2000-01-01	1577
2000-04-01	-150
2000-07-01	159
2000-10-01	-544
2001-01-01	-1242
2001-04-01	-569
2001-07-01	-1191
2001-10-01	1236
2002-01-01	-1788
2002-04-01	1569
2002-07-01	2604
2002-10-01	2724
2003-01-01	463
2003-04-01	2468
2003-07-01	3706
2003-10-01	850
2004-01-01	3767
2004-04-01	2820
2004-07-01	1538
2004-10-01	1016
2005-01-01	2743
2005-04-01	1577
2005-07-01	1369
2005-10-01	5391
2006-01-01	2318
2006-04-01	4602
2006-07-01	4830
2006-10-01	3467
2007-01-01	1061
2007-04-01	8526
2007-07-01	322
2007-10-01	1810
2008-01-01	2260
2008-04-01	3245
2008-07-01	-2096
2008-10-01	-8121
2009-01-01	3084
2009-04-01	11341
2009-07-01	6332
2009-10-01	-2274
2010-01-01	877
2010-04-01	534
2010-07-01	3843
2010-10-01	2447
2011-01-01	5802
2011-04-01	3015
2011-07-01	5404
2011-10-01	5112
2012-01-01	6340
2012-04-01	2378
2012-07-01	8605
2012-10-01	-3512
2013-01-01	3831
2013-04-01	-4964
2013-07-01	12209
2013-10-01	9232
2014-01-01	3547
2014-04-01	-1049
2014-07-01	-763
2014-10-01	7332
2015-01-01	-2352
2015-04-01	2985
2015-07-01	-2500
2015-10-01	-4535
2016-01-01	610
2016-04-01	-923
2016-07-01	1019
2016-10-01	-2517
2017-01-01	4314
2017-04-01	-1866
2017-07-01	3724
2017-10-01	3469
2018-01-01	3002
2018-04-01	6321