Quarter	Millions of US Dollars
1972-04-01	37
1972-10-01	50
1973-04-01	37
1973-10-01	20
1974-01-01	16
1974-04-01	17
1974-10-01	19
1975-01-01	25
1975-10-01	18
1976-04-01	13
1976-07-01	398
1976-10-01	52
1977-01-01	88
1977-04-01	37
1977-07-01	87
1977-10-01	46
1978-01-01	180
1978-04-01	146
1978-07-01	130
1978-10-01	128
1979-01-01	273
1979-04-01	108
1979-07-01	216
1980-04-01	51
1980-07-01	142
1980-10-01	47
1981-04-01	63
1981-07-01	146
1981-10-01	175
1982-01-01	445
1982-04-01	290
1982-07-01	37
1982-10-01	487
1983-01-01	53
1983-04-01	238
1983-07-01	1333
1983-10-01	179
1984-01-01	421
1984-04-01	42
1984-07-01	378
1984-10-01	1086
1985-01-01	735
1985-04-01	1512
1985-07-01	658
1985-10-01	2013
1986-01-01	1334
1986-04-01	534
1986-07-01	191
1986-10-01	260
1987-01-01	320
1987-04-01	230
1987-07-01	493
1987-10-01	473
1988-01-01	-71
1988-04-01	-127
1988-07-01	828
1988-10-01	375
1989-01-01	-76
1989-04-01	-23
1989-07-01	-110
1989-10-01	717
1990-01-01	228
1990-04-01	310
1990-07-01	497
1990-10-01	180
1991-01-01	724
1991-04-01	1778
1991-07-01	146
1991-10-01	484
1992-01-01	478
1992-04-01	114
1992-07-01	1395
1992-10-01	2972
1993-01-01	107
1993-04-01	1204
1993-07-01	1875
1993-10-01	4889
1994-01-01	3500
1994-04-01	3945
1994-07-01	4355
1994-10-01	1560
1995-01-01	996
1995-04-01	2013
1995-07-01	6076
1995-10-01	3121
1996-01-01	4320
1996-04-01	5813
1996-07-01	10433
1996-10-01	12025
1997-01-01	6477
1997-04-01	9480
1997-07-01	7764
1997-10-01	1623
1998-01-01	-629
1998-04-01	4556
1998-07-01	-3373
1998-10-01	-1359
1999-01-01	230
1999-04-01	252
1999-07-01	-3387
1999-10-01	-100
2000-01-01	3471
2000-04-01	-1662
2000-07-01	-1049
2000-10-01	63
2001-01-01	-2702
2001-04-01	1985
2001-07-01	-3601
2001-10-01	2446
2002-01-01	2392
2002-04-01	5854
2002-07-01	3332
2002-10-01	2343
2003-01-01	2340
2003-04-01	4399
2003-07-01	5375
2003-10-01	3191
2004-01-01	8021
2004-04-01	6257
2004-07-01	4901
2004-10-01	6789
2005-01-01	5880
2005-04-01	5719
2005-07-01	5051
2005-10-01	6113
2006-01-01	9886
2006-04-01	4442
2006-07-01	7284
2006-10-01	4706
2007-01-01	7767
2007-04-01	12247
2007-07-01	1427
2007-10-01	5474
2008-01-01	4026
2008-04-01	2678
2008-07-01	-103
2008-10-01	-10825
2009-01-01	5500
2009-04-01	7094
2009-07-01	12604
2009-10-01	4781
2010-01-01	4741
2010-04-01	2307
2010-07-01	4567
2010-10-01	10385
2011-01-01	9632
2011-04-01	10827
2011-07-01	6797
2011-10-01	5084
2012-01-01	13467
2012-04-01	16350
2012-07-01	14946
2012-10-01	6781
2013-01-01	10244
2013-04-01	13397
2013-07-01	19806
2013-10-01	15679
2014-01-01	13653
2014-04-01	13157
2014-07-01	6414
2014-10-01	47301
2015-01-01	13526
2015-04-01	20010
2015-07-01	14262
2015-10-01	8159
2016-01-01	8695
2016-04-01	20326
2016-07-01	15846
2016-10-01	15350
2017-01-01	24291
2017-04-01	11968
2017-07-01	28316
2017-10-01	36516
2018-01-01	22579
2018-04-01	16924