Quarter	Millions of US Dollars
1968-07-01	40
1971-01-01	86
1971-04-01	51
1971-07-01	24
1971-10-01	81
1972-01-01	203
1972-04-01	143
1972-07-01	219
1972-10-01	386
1973-01-01	161
1973-04-01	392
1973-07-01	130
1973-10-01	531
1974-01-01	180
1974-04-01	493
1974-07-01	67
1974-10-01	166
1975-01-01	337
1975-04-01	553
1975-07-01	187
1975-10-01	209
1976-01-01	187
1976-04-01	459
1976-07-01	656
1976-10-01	563
1977-01-01	654
1977-04-01	864
1977-07-01	1280
1977-10-01	1488
1978-01-01	1744
1978-04-01	1356
1978-07-01	901
1978-10-01	1223
1979-01-01	1080
1979-04-01	731
1979-07-01	816
1979-10-01	245
1980-01-01	-89
1980-04-01	608
1980-07-01	591
1980-10-01	259
1981-01-01	165
1981-04-01	691
1981-07-01	677
1981-10-01	973
1982-01-01	1037
1982-04-01	211
1982-07-01	-64
1982-10-01	467
1983-01-01	-305
1983-04-01	126
1983-07-01	1296
1983-10-01	-56
1984-01-01	260
1984-04-01	71
1984-07-01	238
1984-10-01	1302
1985-01-01	988
1985-04-01	2223
1985-07-01	714
1985-10-01	-155
1986-01-01	1149
1986-04-01	433
1986-07-01	111
1986-10-01	-461
1987-01-01	270
1987-04-01	-242
1987-07-01	-145
1987-10-01	-202
1988-01-01	412
1988-04-01	-731
1988-07-01	478
1988-10-01	825
1989-01-01	474
1989-04-01	-215
1989-07-01	2061
1989-10-01	769
1990-01-01	36120
1990-04-01	582
1990-07-01	860
1990-10-01	16739
1991-01-01	2048
1991-04-01	3953
1991-07-01	1479
1991-10-01	4366
1992-01-01	4599
1992-04-01	2607
1992-07-01	3604
1992-10-01	6171
1993-01-01	3738
1993-04-01	23634
1993-07-01	13012
1993-10-01	24625
1994-01-01	14050
1994-04-01	48645
1994-07-01	13526
1994-10-01	11481
1995-01-01	581
1995-04-01	6306
1995-07-01	15066
1995-10-01	9025
1996-01-01	15624
1996-04-01	21170
1996-07-01	17747
1996-10-01	25441
1997-01-01	25300
1997-04-01	31773
1997-07-01	29213
1997-10-01	4769
1998-01-01	13330
1998-04-01	25985
1998-07-01	3481
1998-10-01	-25078
1999-01-01	3499
1999-04-01	17777
1999-07-01	2479
1999-10-01	12451
2000-01-01	23022
2000-04-01	610
2000-07-01	36997
2000-10-01	-3514
2001-01-01	10264
2001-04-01	-124
2001-07-01	-705
2001-10-01	-674
2002-01-01	9924
2002-04-01	5442
2002-07-01	5029
2002-10-01	7528
2003-01-01	4295
2003-04-01	9038
2003-07-01	15856
2003-10-01	14001
2004-01-01	23637
2004-04-01	13330
2004-07-01	13617
2004-10-01	21856
2005-01-01	29067
2005-04-01	-2925
2005-07-01	15492
2005-10-01	34856
2006-01-01	39991
2006-04-01	817
2006-07-01	29096
2006-10-01	62866
2007-01-01	49789
2007-04-01	64789
2007-07-01	3694
2007-10-01	34141
2008-01-01	-2510
2008-04-01	42893
2008-07-01	11270
2008-10-01	-33423
2009-01-01	-3411
2009-04-01	27263
2009-07-01	50116
2009-10-01	54943
2010-01-01	33164
2010-04-01	33139
2010-07-01	66075
2010-10-01	69837
2011-01-01	69255
2011-04-01	66434
2011-07-01	19101
2011-10-01	52772
2012-01-01	95671
2012-04-01	72639
2012-07-01	96048
2012-10-01	106765
2013-01-01	80226
2013-04-01	102871
2013-07-01	70697
2013-10-01	113092
2014-01-01	61953
2014-04-01	112795
2014-07-01	68127
2014-10-01	83921
2015-01-01	47971
2015-04-01	83178
2015-07-01	8055
2015-10-01	13522
2016-01-01	24424
2016-04-01	119416
2016-07-01	79301
2016-10-01	120169
2017-01-01	109080
2017-04-01	111259
2017-07-01	107729
2017-10-01	138000
2018-01-01	104435
2018-04-01	52823