Quarter	Millions of US Dollars
1973-07-01	27
1975-01-01	24
1977-04-01	43
1977-07-01	21
1978-07-01	-48
1981-10-01	30
1982-07-01	23
1984-07-01	-13
1984-10-01	75
1985-01-01	-15
1985-04-01	-26
1985-10-01	40
1986-07-01	73
1986-10-01	55
1987-04-01	64
1988-01-01	156
1988-04-01	6
1988-07-01	-24
1989-04-01	158
1989-07-01	71
1990-01-01	136
1990-04-01	142
1991-01-01	-67
1991-04-01	149
1991-07-01	-50
1991-10-01	-85
1992-01-01	-117
1992-04-01	-1
1992-07-01	-29
1992-10-01	52
1993-01-01	32
1993-04-01	3
1993-07-01	106
1993-10-01	820
1994-01-01	540
1994-04-01	319
1994-07-01	430
1994-10-01	193
1995-01-01	-293
1995-04-01	-292
1995-07-01	53
1995-10-01	301
1996-01-01	81
1996-04-01	301
1996-07-01	116
1996-10-01	7
1997-01-01	369
1997-04-01	4
1997-07-01	800
1997-10-01	-187
1998-01-01	-76
1998-04-01	-81
1998-07-01	106
1998-10-01	261
1999-01-01	938
1999-04-01	-145
1999-07-01	773
1999-10-01	547
2000-01-01	675
2000-04-01	-81
2000-07-01	65
2000-10-01	636
2001-01-01	-515
2001-04-01	2303
2001-07-01	5
2001-10-01	676
2002-01-01	1932
2002-04-01	1023
2002-07-01	-378
2002-10-01	-20
2003-01-01	-64
2003-04-01	173
2003-07-01	638
2003-10-01	-164
2004-01-01	536
2004-04-01	-25
2004-07-01	-557
2004-10-01	-827
2005-01-01	126
2005-04-01	42
2005-07-01	-24
2005-10-01	-452
2006-01-01	123
2006-04-01	-299
2006-07-01	-172
2006-10-01	490
2007-01-01	126
2007-04-01	27
2007-07-01	-64
2007-10-01	-42
2008-01-01	1
2008-04-01	-69
2008-07-01	-12
2008-10-01	1343
2009-01-01	-2248
2009-04-01	2031
2009-07-01	-911
2009-10-01	175
2010-01-01	-350
2010-04-01	352
2010-07-01	161
2010-10-01	-195
2011-01-01	-2260
2011-04-01	2824
2011-07-01	611
2011-10-01	-390
2012-01-01	818
2012-04-01	1477
2012-07-01	102
2012-10-01	2737
2013-01-01	2555
2013-04-01	3710
2013-07-01	-330
2013-10-01	1258
2014-01-01	-66
2014-04-01	2477
2014-07-01	3003
2014-10-01	801
2015-01-01	236
2015-04-01	1139
2015-07-01	410
2015-10-01	-340
2016-01-01	711
2016-04-01	4
2016-07-01	573
2016-10-01	2407
2017-01-01	3506
2017-04-01	352
2017-07-01	53
2017-10-01	1271
2018-01-01	-660
2018-04-01	2378