Quarter	Millions of US Dollars
1972-10-01	50
1974-04-01	17
1976-07-01	367
1976-10-01	11
1977-01-01	38
1977-04-01	37
1977-07-01	44
1978-01-01	114
1978-07-01	26
1978-10-01	76
1979-01-01	30
1979-04-01	28
1979-07-01	100
1980-07-01	71
1981-10-01	55
1982-01-01	30
1983-01-01	-17
1984-01-01	-21
1984-07-01	-34
1985-01-01	-31
1985-10-01	-57
1986-01-01	-16
1986-07-01	-100
1986-10-01	-84
1987-04-01	-70
1987-07-01	-12
1988-01-01	-106
1988-07-01	-32
1988-10-01	-50
1989-01-01	-55
1989-07-01	-70
1990-04-01	837
1990-07-01	-83
1991-10-01	-116
1992-01-01	-207
1992-10-01	3348
1993-01-01	150
1993-07-01	305
1993-10-01	454
1994-01-01	38
1994-04-01	405
1994-07-01	310
1994-10-01	329
1995-04-01	-76
1995-07-01	398
1995-10-01	162
1996-01-01	15
1996-04-01	556
1996-07-01	587
1996-10-01	1725
1997-01-01	954
1997-04-01	863
1997-07-01	1197
1997-10-01	-319
1998-01-01	812
1998-04-01	739
1998-07-01	-399
1998-10-01	-503
1999-01-01	1197
1999-04-01	754
1999-07-01	766
1999-10-01	361
2000-01-01	1574
2000-04-01	-316
2000-07-01	176
2000-10-01	-309
2001-01-01	-862
2001-04-01	266
2001-07-01	-190
2001-10-01	1216
2002-01-01	1641
2002-04-01	831
2002-07-01	449
2002-10-01	940
2003-01-01	883
2003-04-01	801
2003-07-01	497
2003-10-01	1381
2004-01-01	383
2004-04-01	143
2004-07-01	959
2004-10-01	-166
2005-01-01	1525
2005-04-01	684
2005-07-01	943
2005-10-01	-1117
2006-01-01	2521
2006-04-01	-528
2006-07-01	1401
2006-10-01	-773
2007-01-01	1455
2007-04-01	317
2007-07-01	-416
2007-10-01	-418
2008-01-01	219
2008-04-01	-1426
2008-07-01	154
2008-10-01	-275
2009-01-01	505
2009-04-01	834
2009-07-01	1244
2009-10-01	1730
2010-01-01	994
2010-04-01	-29
2010-07-01	681
2010-10-01	1098
2011-01-01	2001
2011-04-01	1075
2011-07-01	-400
2011-10-01	-950
2012-01-01	2487
2012-04-01	349
2012-07-01	-98
2012-10-01	1143
2013-01-01	-622
2013-04-01	1850
2013-07-01	-599
2013-10-01	500
2014-01-01	-200
2014-04-01	575
2014-07-01	-372
2015-01-01	2329
2015-04-01	-32
2015-07-01	345
2015-10-01	221
2016-01-01	575
2016-04-01	-650
2016-10-01	-714
2017-01-01	-832
2017-07-01	1800
2017-10-01	-968
2018-01-01	3661
2018-04-01	298