Quarter	Millions of US Dollars
1972-10-01	45
1973-01-01	15
1981-07-01	30
1982-10-01	50
1983-01-01	21
1983-07-01	21
1984-04-01	150
1984-07-01	27
1984-10-01	4
1985-01-01	297
1985-04-01	162
1985-07-01	283
1986-04-01	30
1986-07-01	53
1986-10-01	-180
1987-01-01	114
1987-04-01	170
1987-07-01	83
1987-10-01	-25
1988-01-01	166
1988-04-01	120
1988-07-01	150
1989-01-01	486
1989-04-01	153
1989-10-01	439
1990-01-01	111
1990-07-01	537
1990-10-01	227
1991-01-01	1399
1991-04-01	708
1991-07-01	-48
1991-10-01	377
1992-01-01	547
1992-04-01	809
1992-07-01	506
1992-10-01	613
1993-01-01	967
1993-04-01	761
1993-07-01	526
1993-10-01	1574
1994-01-01	-302
1994-04-01	588
1994-07-01	1200
1994-10-01	1868
1995-01-01	189
1995-04-01	-507
1995-07-01	989
1995-10-01	750
1996-01-01	1991
1996-04-01	-59
1996-07-01	1431
1996-10-01	354
1997-01-01	-59
1997-04-01	-348
1997-07-01	-234
1997-10-01	2390
1998-01-01	3632
1998-04-01	-189
1998-07-01	-411
1998-10-01	-519
1999-01-01	1453
1999-04-01	418
1999-07-01	164
1999-10-01	-677
2000-01-01	3168
2000-04-01	529
2000-07-01	746
2000-10-01	-285
2001-01-01	-312
2001-04-01	362
2001-07-01	1708
2001-10-01	358
2002-01-01	5069
2002-04-01	737
2002-07-01	-147
2002-10-01	-476
2003-01-01	9181
2003-04-01	3496
2003-07-01	1936
2003-10-01	1943
2004-01-01	2219
2004-04-01	5117
2004-07-01	1685
2004-10-01	1428
2005-01-01	5328
2005-04-01	5545
2005-07-01	87
2005-10-01	2144
2006-01-01	7481
2006-04-01	8234
2006-07-01	2980
2006-10-01	10269
2007-01-01	16833
2007-04-01	13974
2007-07-01	-3213
2007-10-01	-1512
2008-01-01	2558
2008-04-01	12571
2008-07-01	-2055
2008-10-01	7055
2009-01-01	17335
2009-04-01	18106
2009-07-01	6821
2009-10-01	-14956
2010-01-01	5100
2010-04-01	39207
2010-07-01	5061
2010-10-01	24212
2011-01-01	-5340
2011-04-01	5096
2011-07-01	-1649
2011-10-01	8365
2012-01-01	-24107
2012-04-01	-20346
2012-07-01	-19783
2012-10-01	-1072
2013-01-01	-4981
2013-04-01	-10649
2013-07-01	-8569
2013-10-01	-323
2014-01-01	-650
2014-04-01	3362
2014-07-01	1547
2014-10-01	2131
2015-01-01	-1864
2015-04-01	10077
2015-07-01	349
2015-10-01	-11463
2016-01-01	-13490
2016-04-01	-25895
2016-07-01	-11096
2016-10-01	-4231
2017-01-01	-2491
2017-04-01	-11970
2017-07-01	-5186
2017-10-01	2134
2018-01-01	6487
2018-04-01	1669