Quarter	Millions of US Dollars
1971-01-01	40
1971-04-01	40
1971-07-01	2
1971-10-01	2
1972-01-01	96
1972-04-01	98
1972-07-01	26
1972-10-01	25
1973-01-01	74
1973-04-01	12
1974-01-01	167
1974-04-01	27
1974-07-01	256
1974-10-01	164
1975-01-01	643
1975-04-01	523
1975-07-01	317
1975-10-01	494
1976-01-01	922
1976-04-01	945
1976-07-01	509
1976-10-01	574
1977-01-01	452
1977-04-01	296
1977-07-01	227
1977-10-01	677
1978-01-01	412
1978-04-01	464
1978-07-01	353
1978-10-01	81
1979-01-01	358
1979-04-01	649
1979-07-01	545
1979-10-01	510
1980-01-01	86
1980-04-01	559
1980-07-01	217
1980-10-01	773
1981-01-01	808
1981-04-01	208
1981-07-01	169
1981-10-01	506
1982-01-01	1885
1982-04-01	1885
1982-07-01	1763
1982-10-01	1537
1983-01-01	1975
1983-04-01	1528
1983-07-01	544
1983-10-01	1331
1984-01-01	2106
1984-04-01	719
1984-07-01	2496
1984-10-01	1448
1985-01-01	2013
1985-04-01	454
1985-07-01	1477
1985-10-01	-191
1986-01-01	-15
1986-04-01	1924
1986-07-01	1216
1986-10-01	1156
1987-01-01	593
1987-04-01	930
1987-07-01	-457
1987-10-01	75
1988-01-01	2193
1988-04-01	2934
1988-07-01	1968
1988-10-01	638
1989-01-01	2303
1989-04-01	1291
1989-07-01	1077
1989-10-01	1614
1990-01-01	2171
1990-04-01	1701
1990-07-01	3123
1990-10-01	1605
1991-01-01	2982
1991-04-01	4626
1991-07-01	3633
1991-10-01	6009
1992-01-01	5518
1992-04-01	4156
1992-07-01	1999
1992-10-01	6664
1993-01-01	4373
1993-04-01	1797
1993-07-01	13931
1993-10-01	6358
1994-01-01	5374
1994-04-01	351
1994-07-01	2454
1994-10-01	2679
1995-01-01	50
1995-04-01	-871
1995-07-01	651
1995-10-01	4868
1996-01-01	-846
1996-04-01	8126
1996-07-01	4288
1996-10-01	937
1997-01-01	5675
1997-04-01	899
1997-07-01	3664
1997-10-01	924
1998-01-01	11694
1998-04-01	4202
1998-07-01	7112
1998-10-01	6483
1999-01-01	12101
1999-04-01	13192
1999-07-01	7288
1999-10-01	13568
2000-01-01	10082
2000-04-01	13508
2000-07-01	17094
2000-10-01	12522
2001-01-01	30707
2001-04-01	16169
2001-07-01	15137
2001-10-01	22644
2002-01-01	4068
2002-04-01	18954
2002-07-01	9458
2002-10-01	15390
2003-01-01	23841
2003-04-01	34866
2003-07-01	14212
2003-10-01	20532
2004-01-01	11249
2004-04-01	18206
2004-07-01	23154
2004-10-01	36075
2005-01-01	23928
2005-04-01	35369
2005-07-01	5989
2005-10-01	28547
2006-01-01	26238
2006-04-01	27266
2006-07-01	9134
2006-10-01	75242
2007-01-01	28280
2007-04-01	57399
2007-07-01	-5495
2007-10-01	37110
2008-01-01	20900
2008-04-01	86595
2008-07-01	21219
2008-10-01	2191
2009-01-01	38666
2009-04-01	97606
2009-07-01	28501
2009-10-01	42692
2010-01-01	80446
2010-04-01	10472
2010-07-01	37755
2010-10-01	27231
2011-01-01	72958
2011-04-01	11689
2011-07-01	-12855
2011-10-01	10694
2012-01-01	15581
2012-04-01	-19435
2012-07-01	3475
2012-10-01	-6408
2013-01-01	-11381
2013-04-01	-1576
2013-07-01	-2194
2013-10-01	1291
2014-01-01	22668
2014-04-01	12118
2014-07-01	16556
2014-10-01	-27331
2015-01-01	19565
2015-04-01	-32527
2015-07-01	-21065
2015-10-01	-6091
2016-01-01	5427
2016-04-01	23852
2016-07-01	11933
2016-10-01	8913
2017-01-01	-4636
2017-04-01	-5163
2017-07-01	-6880
2017-10-01	13230
2018-01-01	-7071
2018-04-01	3535