Quarter	Millions of US Dollars
1971-01-01	15
1971-10-01	48
1972-01-01	79
1972-04-01	32
1972-07-01	120
1972-10-01	66
1973-01-01	63
1973-04-01	13
1973-07-01	69
1974-01-01	31
1974-04-01	2
1974-10-01	60
1975-01-01	146
1975-04-01	28
1975-07-01	155
1975-10-01	87
1976-01-01	67
1976-04-01	35
1976-07-01	65
1976-10-01	181
1977-01-01	58
1977-04-01	80
1977-07-01	73
1977-10-01	186
1978-01-01	326
1978-04-01	296
1978-07-01	153
1978-10-01	242
1979-01-01	301
1979-04-01	138
1979-07-01	29
1979-10-01	164
1980-01-01	-6
1980-04-01	70
1980-07-01	-24
1980-10-01	-8
1981-01-01	14
1981-04-01	259
1981-07-01	25
1981-10-01	205
1982-01-01	95
1982-04-01	150
1982-07-01	184
1982-10-01	146
1983-01-01	124
1983-04-01	215
1983-07-01	118
1983-10-01	-26
1984-01-01	197
1984-04-01	268
1984-07-01	190
1984-10-01	130
1985-01-01	279
1985-04-01	131
1985-07-01	31
1985-10-01	-145
1986-01-01	377
1986-04-01	453
1986-07-01	422
1986-10-01	161
1987-01-01	660
1987-04-01	278
1987-07-01	-122
1987-10-01	659
1988-01-01	587
1988-04-01	1185
1988-07-01	101
1988-10-01	564
1989-01-01	882
1989-04-01	593
1989-07-01	351
1989-10-01	332
1990-01-01	689
1990-04-01	1005
1990-07-01	1243
1990-10-01	1906
1991-01-01	1116
1991-04-01	720
1991-07-01	1157
1991-10-01	1569
1992-01-01	1541
1992-04-01	3874
1992-07-01	2258
1992-10-01	3250
1993-01-01	2870
1993-04-01	1048
1993-07-01	900
1993-10-01	-1072
1994-01-01	1417
1994-04-01	1870
1994-07-01	3781
1994-10-01	-7
1995-01-01	494
1995-04-01	-747
1995-07-01	-392
1995-10-01	-1353
1996-01-01	2227
1996-04-01	-590
1996-07-01	-990
1996-10-01	950
1997-01-01	1601
1997-04-01	-439
1997-07-01	-1503
1997-10-01	-1411
1998-01-01	-2560
1998-04-01	204
1998-07-01	-31
1998-10-01	-2004
1999-01-01	-1190
1999-04-01	83
1999-07-01	1276
1999-10-01	60
2000-01-01	-1921
2000-04-01	713
2000-07-01	-347
2000-10-01	-1128
2001-01-01	-546
2001-04-01	5258
2001-07-01	-1327
2001-10-01	-53
2002-01-01	1628
2002-04-01	-1247
2002-07-01	-1146
2002-10-01	775
2003-01-01	7131
2003-04-01	4151
2003-07-01	2341
2003-10-01	-2159
2004-01-01	3659
2004-04-01	1509
2004-07-01	-1935
2004-10-01	1301
2005-01-01	1968
2005-04-01	82
2005-07-01	222
2005-10-01	1029
2006-01-01	4192
2006-04-01	2480
2006-07-01	-7942
2006-10-01	467
2007-01-01	-1868
2007-04-01	1223
2007-07-01	-6417
2007-10-01	-2557
2008-01-01	-2308
2008-04-01	1044
2008-07-01	-4710
2008-10-01	2620
2009-01-01	6237
2009-04-01	3292
2009-07-01	2175
2009-10-01	2535
2010-01-01	3365
2010-04-01	573
2010-07-01	1859
2010-10-01	4271
2011-01-01	14413
2011-04-01	-616
2011-07-01	-1033
2011-10-01	215
2012-01-01	7930
2012-04-01	6456
2012-07-01	-779
2012-10-01	3968
2013-01-01	5152
2013-04-01	3925
2013-07-01	4695
2013-10-01	3993
2014-01-01	3606
2014-04-01	7923
2014-07-01	3090
2014-10-01	1102
2015-01-01	2042
2015-04-01	6018
2015-07-01	5548
2015-10-01	-1304
2016-01-01	-2270
2016-04-01	5015
2016-07-01	2597
2016-10-01	4245
2017-01-01	3270
2017-04-01	748
2017-07-01	5833
2017-10-01	4351
2018-01-01	5398
2018-04-01	-2111