Quarter	Millions of US Dollars
1972-07-01	50
1973-04-01	30
1974-04-01	52
1975-01-01	60
1975-04-01	80
1975-10-01	19
1976-01-01	25
1976-04-01	41
1976-07-01	17
1977-01-01	30
1977-04-01	20
1977-07-01	143
1977-10-01	111
1978-04-01	47
1979-04-01	96
1980-01-01	-25
1980-04-01	50
1980-07-01	12
1981-01-01	-30
1981-04-01	-92
1982-07-01	-27
1982-10-01	-20
1983-01-01	-60
1983-04-01	-60
1983-07-01	-35
1983-10-01	-17
1984-04-01	-51
1984-07-01	50
1984-10-01	-1
1985-01-01	170
1985-04-01	-22
1985-07-01	152
1985-10-01	-57
1986-01-01	162
1986-04-01	386
1986-07-01	72
1986-10-01	104
1987-01-01	354
1987-04-01	-5
1987-07-01	-3
1987-10-01	391
1988-01-01	766
1988-04-01	455
1988-07-01	541
1988-10-01	668
1989-01-01	920
1989-04-01	293
1989-07-01	1303
1989-10-01	497
1990-01-01	750
1990-04-01	268
1990-07-01	458
1990-10-01	460
1991-01-01	128
1991-04-01	321
1991-07-01	100
1991-10-01	1417
1992-01-01	819
1992-04-01	282
1992-07-01	1252
1992-10-01	913
1993-01-01	2317
1993-04-01	1272
1993-07-01	2003
1993-10-01	2211
1994-01-01	1360
1994-04-01	297
1994-07-01	5586
1994-10-01	6485
1995-01-01	-811
1995-04-01	388
1995-07-01	1748
1995-10-01	848
1996-01-01	432
1996-04-01	2004
1996-07-01	-1893
1996-10-01	375
1997-01-01	2664
1997-04-01	4834
1997-07-01	4643
1997-10-01	2317
1998-01-01	2445
1998-04-01	5619
1998-07-01	6076
1998-10-01	-1192
1999-01-01	1157
1999-04-01	680
1999-07-01	-56
1999-10-01	3922
2000-01-01	2339
2000-04-01	2948
2000-07-01	20927
2000-10-01	-605
2001-01-01	1787
2001-04-01	420
2001-07-01	-43
2001-10-01	1248
2002-01-01	1138
2002-04-01	297
2002-07-01	759
2002-10-01	1190
2003-01-01	5323
2003-04-01	888
2003-07-01	4322
2003-10-01	2930
2004-01-01	3723
2004-04-01	8189
2004-07-01	4468
2004-10-01	4979
2005-01-01	11056
2005-04-01	16898
2005-07-01	758
2005-10-01	10386
2006-01-01	12106
2006-04-01	2453
2006-07-01	8515
2006-10-01	20905
2007-01-01	15859
2007-04-01	18142
2007-07-01	1350
2007-10-01	12884
2008-01-01	-1491
2008-04-01	22461
2008-07-01	5793
2008-10-01	-5174
2009-01-01	-2312
2009-04-01	7163
2009-07-01	5638
2009-10-01	7393
2010-01-01	9855
2010-04-01	8287
2010-07-01	17605
2010-10-01	18212
2011-01-01	14568
2011-04-01	14436
2011-07-01	-718
2011-10-01	1162
2012-01-01	17135
2012-04-01	24898
2012-07-01	41341
2012-10-01	36175
2013-01-01	15609
2013-04-01	22381
2013-07-01	10693
2013-10-01	26309
2014-01-01	-8601
2014-04-01	-376
2014-07-01	1633
2014-10-01	7800
2015-01-01	-1810
2015-04-01	-6053
2015-07-01	-7678
2015-10-01	-21737
2016-01-01	-2485
2016-04-01	9424
2016-07-01	-6654
2016-10-01	13941
2017-01-01	-581
2017-04-01	7593
2017-07-01	6944
2017-10-01	4752
2018-01-01	-2170
2018-04-01	-18862