Quarter	Millions of US Dollars
1980-07-01	25
1982-01-01	43
1982-04-01	20
1983-04-01	40
1983-07-01	20
1984-10-01	83
1985-01-01	116
1985-04-01	129
1985-07-01	294
1985-10-01	206
1986-01-01	353
1986-04-01	389
1986-07-01	329
1986-10-01	156
1987-01-01	192
1987-04-01	200
1987-07-01	216
1987-10-01	364
1988-01-01	230
1988-04-01	158
1988-07-01	239
1988-10-01	194
1989-04-01	154
1990-07-01	-39
1991-07-01	143
1991-10-01	22
1992-01-01	-155
1992-04-01	48
1992-07-01	219
1992-10-01	-4
1993-01-01	-290
1993-04-01	336
1993-07-01	1341
1993-10-01	334
1994-01-01	1407
1994-04-01	422
1994-07-01	1219
1994-10-01	458
1995-01-01	-142
1995-04-01	-237
1995-07-01	759
1995-10-01	-105
1996-01-01	-93
1996-04-01	-71
1996-07-01	1357
1996-10-01	308
1997-01-01	668
1997-04-01	1458
1997-07-01	2
1997-10-01	414
1998-01-01	10
1998-04-01	-770
1998-07-01	-861
1998-10-01	611
1999-01-01	-450
1999-04-01	227
1999-07-01	-426
1999-10-01	-82
2000-01-01	-289
2000-04-01	29
2000-07-01	-247
2001-01-01	-150
2001-04-01	1359
2001-07-01	-1407
2001-10-01	151
2002-01-01	860
2002-04-01	-1135
2002-07-01	-404
2002-10-01	-939
2003-01-01	-300
2003-07-01	-133
2003-10-01	965
2004-01-01	-850
2004-04-01	-500
2004-07-01	530
2004-10-01	2822
2005-01-01	-96
2005-04-01	-200
2005-07-01	1230
2005-10-01	1000
2006-01-01	-257
2006-04-01	-779
2006-07-01	-509
2006-10-01	-150
2007-01-01	776
2007-04-01	2047
2007-07-01	1134
2007-10-01	262
2008-01-01	575
2008-04-01	4
2008-07-01	2306
2008-10-01	-1526
2009-04-01	-483
2009-07-01	878
2009-10-01	881
2010-01-01	58
2010-04-01	-386
2010-07-01	-1125
2010-10-01	2034
2011-01-01	525
2011-04-01	1748
2011-07-01	504
2011-10-01	640
2012-01-01	1056
2012-04-01	7815
2012-07-01	2249
2012-10-01	2169
2013-01-01	2006
2013-04-01	2060
2013-07-01	1522
2013-10-01	4311
2014-01-01	1907
2014-04-01	3315
2014-07-01	2329
2014-10-01	27842
2015-01-01	-423
2015-04-01	2563
2015-07-01	6715
2015-10-01	8562
2016-01-01	4338
2016-04-01	16418
2016-07-01	12749
2016-10-01	8732
2017-01-01	11891
2017-04-01	1450
2017-07-01	11230
2017-10-01	24545
2018-01-01	9602
2018-04-01	1628