Quarter	Millions of US Dollars
1975-04-01	16
1977-07-01	68
1978-01-01	87
1978-04-01	98
1978-10-01	81
1979-01-01	104
1979-04-01	179
1979-07-01	47
1979-10-01	87
1980-07-01	140
1980-10-01	25
1981-04-01	115
1981-10-01	50
1982-04-01	-16
1982-07-01	-25
1983-04-01	-30
1984-04-01	-66
1984-07-01	-34
1985-01-01	-46
1985-10-01	-62
1986-01-01	-93
1986-04-01	-92
1986-10-01	-57
1987-04-01	-103
1987-07-01	-16
1987-10-01	-25
1988-01-01	-18
1988-10-01	-70
1989-04-01	-23
1989-07-01	-39
1989-10-01	-112
1990-01-01	-15
1990-07-01	-168
1990-10-01	21
1991-04-01	15
1991-10-01	725
1992-01-01	245
1992-04-01	250
1992-07-01	520
1992-10-01	394
1993-01-01	404
1993-04-01	17561
1993-07-01	1064
1993-10-01	12002
1994-01-01	1537
1994-04-01	64
1994-07-01	1178
1994-10-01	2289
1995-01-01	-676
1995-04-01	1834
1995-07-01	1723
1995-10-01	2375
1996-01-01	2121
1996-04-01	4020
1996-07-01	1678
1996-10-01	3378
1997-01-01	5879
1997-04-01	2045
1997-07-01	6556
1997-10-01	275
1998-01-01	3526
1998-04-01	7226
1998-07-01	1529
1998-10-01	-5928
1999-01-01	1687
1999-04-01	4400
1999-07-01	1750
1999-10-01	2828
2000-01-01	5146
2000-04-01	3763
2000-07-01	2349
2000-10-01	-1839
2001-01-01	1555
2001-04-01	4394
2001-07-01	-830
2001-10-01	-619
2002-01-01	-575
2002-04-01	-454
2002-07-01	-1230
2002-10-01	-436
2003-01-01	-1273
2003-04-01	-957
2003-07-01	-1044
2003-10-01	38
2004-01-01	-542
2004-04-01	-2546
2004-07-01	-1343
2004-10-01	-41
2005-01-01	-90
2005-04-01	-30515
2005-07-01	-111
2005-10-01	362
2006-01-01	207
2006-04-01	-384
2006-07-01	34
2006-10-01	586
2007-01-01	-362
2007-04-01	1616
2007-07-01	1222
2007-10-01	394
2008-01-01	-1691
2008-04-01	-1861
2008-07-01	-553
2008-10-01	-7049
2009-01-01	-790
2009-04-01	-1194
2009-07-01	-2150
2009-10-01	-355
2010-01-01	-289
2010-04-01	1409
2010-07-01	609
2010-10-01	853
2011-01-01	1257
2011-04-01	69
2011-07-01	-574
2011-10-01	-349
2012-01-01	-529
2012-04-01	-427
2012-07-01	-67
2012-10-01	-97
2013-01-01	-100
2013-04-01	-7
2013-10-01	-176
2014-01-01	-98
2014-04-01	958
2014-07-01	-318
2014-10-01	-738
2015-01-01	1537
2015-04-01	774
2015-07-01	69
2015-10-01	-740
2016-01-01	2620
2016-04-01	20106
2016-07-01	6311
2016-10-01	4766
2017-01-01	12372
2017-04-01	13314
2017-07-01	1451
2017-10-01	6246
2018-01-01	10244
2018-04-01	-2230