Quarter	Millions of US Dollars
1966-01-01	15
1972-01-01	50
1972-04-01	15
1974-07-01	34
1974-10-01	84
1975-01-01	31
1975-04-01	87
1975-07-01	286
1975-10-01	33
1976-04-01	150
1976-07-01	71
1976-10-01	191
1977-01-01	30
1977-04-01	231
1977-07-01	173
1977-10-01	110
1978-01-01	303
1978-04-01	174
1978-10-01	316
1979-01-01	96
1979-04-01	152
1979-07-01	157
1979-10-01	0
1980-04-01	94
1980-07-01	-12
1980-10-01	25
1981-01-01	97
1981-04-01	114
1981-07-01	-6
1981-10-01	249
1982-01-01	443
1982-04-01	180
1982-07-01	32
1982-10-01	486
1983-01-01	280
1983-04-01	-126
1983-07-01	-38
1984-01-01	136
1984-04-01	105
1984-07-01	84
1984-10-01	616
1985-01-01	34
1985-04-01	225
1985-07-01	522
1985-10-01	-71
1986-01-01	506
1986-04-01	516
1986-07-01	1007
1986-10-01	325
1987-01-01	544
1987-04-01	420
1987-07-01	-307
1987-10-01	-91
1988-01-01	-351
1988-04-01	878
1988-07-01	-109
1988-10-01	110
1989-01-01	-570
1989-04-01	-34
1989-07-01	27
1989-10-01	327
1990-01-01	-199
1990-04-01	264
1990-07-01	-55
1990-10-01	-330
1991-01-01	-57
1991-04-01	3
1991-07-01	-197
1991-10-01	-745
1992-01-01	69
1992-04-01	-1206
1992-07-01	-207
1992-10-01	-323
1993-01-01	-833
1993-04-01	-498
1993-07-01	609
1993-10-01	31
1994-01-01	33
1994-04-01	171
1994-07-01	257
1994-10-01	-202
1995-01-01	-101
1995-04-01	-468
1995-07-01	-190
1995-10-01	-66
1996-01-01	80
1996-04-01	-468
1996-07-01	-763
1996-10-01	226
1997-01-01	-337
1997-04-01	344
1997-07-01	-136
1997-10-01	740
1998-01-01	164
1998-04-01	-544
1998-07-01	-259
1998-10-01	188
1999-01-01	-63
1999-04-01	-568
1999-07-01	492
1999-10-01	-99
2000-01-01	195
2000-04-01	329
2000-07-01	-383
2000-10-01	518
2001-01-01	-239
2001-04-01	637
2001-07-01	-423
2001-10-01	240
2002-01-01	-284
2002-04-01	730
2002-07-01	229
2002-10-01	-742
2003-01-01	1674
2003-04-01	-48
2003-07-01	-881
2003-10-01	196
2004-01-01	1447
2004-04-01	777
2004-07-01	2206
2004-10-01	3204
2005-01-01	1523
2005-04-01	-57
2005-07-01	17
2005-10-01	-176
2006-01-01	-673
2006-04-01	273
2006-07-01	-166
2006-10-01	-1338
2007-01-01	-1476
2007-04-01	-347
2007-07-01	189
2007-10-01	1845
2008-01-01	1220
2008-04-01	-3960
2008-07-01	-1787
2008-10-01	-1387
2009-01-01	-1129
2009-04-01	-449
2009-07-01	-2478
2009-10-01	1816
2010-01-01	-1180
2010-04-01	-9
2010-07-01	-158
2010-10-01	3683
2011-01-01	2861
2011-04-01	-266
2011-07-01	2882
2011-10-01	782
2012-01-01	1317
2012-04-01	-270
2012-07-01	1704
2012-10-01	-347
2013-01-01	537
2013-04-01	150
2013-07-01	610
2013-10-01	789
2014-01-01	-3185
2014-04-01	975
2014-07-01	-266
2014-10-01	-171
2015-01-01	-221
2015-04-01	124
2015-07-01	225
2015-10-01	52
2016-01-01	456
2016-04-01	3926
2016-07-01	-1307
2016-10-01	-2640
2017-01-01	89
2017-04-01	175
2017-07-01	1407
2017-10-01	1656
2018-01-01	-34
2018-04-01	-154