Quarter	Millions of US Dollars
1971-04-01	10
1982-01-01	508
1982-10-01	535
1983-10-01	516
1984-07-01	500
1984-10-01	1000
1985-04-01	648
1985-07-01	534
1985-10-01	541
1986-01-01	-149
1986-04-01	295
1986-07-01	4
1986-10-01	289
1987-01-01	4
1987-04-01	221
1987-07-01	5
1987-10-01	3147
1988-01-01	5
1988-04-01	6
1988-07-01	1005
1988-10-01	6
1989-01-01	-58
1989-04-01	79
1989-07-01	6
1989-10-01	-332
1990-01-01	6
1990-04-01	2713
1990-07-01	1236
1990-10-01	-470
1991-01-01	5242
1991-04-01	-211
1991-07-01	7
1991-10-01	-93
1992-01-01	-602
1992-04-01	17
1992-07-01	18
1992-10-01	-226
1993-01-01	3007
1993-04-01	2818
1993-07-01	5916
1993-10-01	18
1994-01-01	2673
1994-04-01	18
1994-07-01	4108
1994-10-01	3087
1995-01-01	-28
1995-04-01	6568
1995-07-01	1324
1995-10-01	625
1996-01-01	-161
1996-04-01	3000
1996-07-01	1529
1996-10-01	918
1997-01-01	801
1997-04-01	1829
1997-07-01	1929
1997-10-01	-365
1998-01-01	1766
1998-04-01	1789
1998-07-01	-1037
1998-10-01	1698
1999-01-01	-2119
1999-04-01	3739
1999-07-01	-2379
1999-10-01	336
2000-01-01	5403
2000-04-01	7962
2000-07-01	-342
2000-10-01	758
2001-01-01	7827
2001-04-01	-1905
2001-07-01	-1051
2001-10-01	4239
2002-01-01	6815
2002-04-01	-2653
2002-07-01	2919
2002-10-01	1996
2003-01-01	11151
2003-04-01	126
2003-07-01	6527
2003-10-01	3221
2004-01-01	13530
2004-04-01	7814
2004-07-01	-2319
2004-10-01	-510
2005-01-01	2374
2005-04-01	3009
2005-07-01	793
2005-10-01	-814
2006-01-01	-11
2006-04-01	2893
2006-07-01	1172
2006-10-01	-8676
2007-01-01	-223
2007-04-01	8801
2007-07-01	-6894
2007-10-01	-2445
2008-01-01	1075
2008-04-01	66
2008-07-01	-23721
2008-10-01	-2524
2009-01-01	1837
2009-04-01	-1198
2009-07-01	-3504
2009-10-01	6057
2010-01-01	1394
2010-04-01	5321
2010-07-01	10776
2010-10-01	2538
2011-01-01	-1526
2011-04-01	1743
2011-07-01	3090
2011-10-01	-3620
2012-01-01	2323
2012-04-01	-2936
2012-07-01	-598
2012-10-01	-4185
2013-01-01	-924
2013-04-01	-1282
2013-07-01	-1530
2013-10-01	-899
2014-01-01	249
2014-04-01	-474
2014-07-01	-7215
2014-10-01	-377
2015-01-01	-5732
2015-04-01	-306
2015-10-01	-6095
2016-01-01	-2000
2016-04-01	2165
2016-07-01	-6454
2016-10-01	5110
2017-01-01	-1040
2017-04-01	6363
2017-07-01	-294
2017-10-01	-6585
2018-01-01	-2484
2018-04-01	-1567