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	132
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
1979-01-01	65
1979-07-01	173
1979-10-01	7
1980-01-01	-37
1980-04-01	201
1980-07-01	25
1980-10-01	75
1981-01-01	75
1981-04-01	539
1981-07-01	420
1981-10-01	790
1982-01-01	629
1982-04-01	133
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	-313
1986-04-01	-151
1986-07-01	-110
1986-10-01	-362
1987-01-01	-271
1987-04-01	-195
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	-49
1989-07-01	-85
1989-10-01	31
1990-01-01	35347
1990-04-01	497
1990-07-01	763
1990-10-01	223
1991-01-01	339
1991-04-01	975
1991-07-01	467
1991-10-01	791
1992-01-01	192
1992-04-01	76
1992-07-01	489
1992-10-01	2202
1993-01-01	588
1993-04-01	2151
1993-07-01	2515
1993-10-01	1959
1994-01-01	4610
1994-04-01	1221
1994-07-01	1427
1994-10-01	-1211
1995-01-01	-3481
1995-04-01	-398
1995-07-01	2650
1995-10-01	909
1996-01-01	2835
1996-04-01	367
1996-07-01	7125
1996-10-01	695
1997-01-01	2636
1997-04-01	5319
1997-07-01	-3565
1997-10-01	-67
1998-01-01	1835
1998-04-01	-210
1998-07-01	360
1998-10-01	-553
1999-01-01	168
1999-04-01	4422
1999-07-01	296
1999-10-01	1277
2000-01-01	3062
2000-04-01	-363
2000-07-01	1266
2000-10-01	-2587
2001-01-01	5316
2001-04-01	-4166
2001-07-01	1198
2001-10-01	-5608
2002-01-01	-177
2002-04-01	-5139
2002-07-01	-294
2002-10-01	833
2003-01-01	-8318
2003-04-01	-3229
2003-07-01	-3994
2003-10-01	1038
2004-01-01	1146
2004-04-01	-887
2004-07-01	231
2004-10-01	101
2005-01-01	2822
2005-04-01	658
2005-07-01	145
2005-10-01	702
2006-01-01	716
2006-04-01	-1193
2006-07-01	-1214
2006-10-01	824
2007-01-01	-560
2007-04-01	400
2007-07-01	579
2007-10-01	1763
2008-01-01	-997
2008-04-01	-656
2008-07-01	-559
2008-10-01	-1475
2009-01-01	-1246
2009-04-01	2794
2009-07-01	4090
2009-10-01	8405
2010-01-01	4607
2010-04-01	7220
2010-07-01	3594
2010-10-01	176
2011-01-01	4640
2011-04-01	5462
2011-07-01	5651
2011-10-01	4729
2012-01-01	7183
2012-04-01	2549
2012-07-01	9550
2012-10-01	6368
2013-01-01	3894
2013-04-01	5691
2013-07-01	10372
2013-10-01	15336
2014-01-01	7080
2014-04-01	10769
2014-07-01	3754
2014-10-01	6437
2015-01-01	7901
2015-04-01	7756
2015-07-01	-134
2015-10-01	3404
2016-01-01	20987
2016-04-01	3722
2016-07-01	1959
2016-10-01	6026
2017-01-01	5489
2017-04-01	-4204
2017-07-01	12319
2017-10-01	478
2018-01-01	9463
2018-04-01	5056