Quarter	Millions of US Dollars
1970-10-01	15
1971-01-01	25
1971-10-01	105
1972-01-01	115
1972-04-01	142
1972-07-01	172
1972-10-01	159
1973-01-01	429
1973-04-01	284
1973-07-01	238
1973-10-01	184
1974-01-01	107
1974-04-01	64
1974-07-01	40
1974-10-01	95
1975-04-01	216
1975-07-01	110
1975-10-01	60
1976-01-01	350
1976-04-01	322
1976-07-01	100
1976-10-01	210
1977-01-01	188
1977-04-01	271
1977-07-01	164
1977-10-01	228
1978-01-01	408
1978-04-01	414
1978-07-01	160
1978-10-01	6
1979-01-01	143
1979-04-01	129
1979-07-01	31
1979-10-01	155
1980-01-01	-34
1980-04-01	25
1980-07-01	-50
1980-10-01	-176
1981-01-01	5
1981-04-01	-130
1981-07-01	-78
1981-10-01	-160
1982-01-01	-13
1982-04-01	-93
1982-07-01	-50
1982-10-01	100
1983-01-01	-72
1983-04-01	-120
1983-07-01	-34
1983-10-01	-38
1984-01-01	-183
1984-04-01	-28
1984-07-01	100
1984-10-01	262
1985-01-01	-123
1985-04-01	95
1985-07-01	809
1985-10-01	3932
1986-01-01	211
1986-04-01	1135
1986-07-01	1304
1986-10-01	791
1987-01-01	1034
1987-04-01	1281
1987-07-01	75
1987-10-01	813
1988-01-01	1069
1988-04-01	2902
1988-07-01	3544
1988-10-01	-490
1989-01-01	2942
1989-04-01	434
1989-07-01	5018
1989-10-01	5124
1990-01-01	5157
1990-04-01	2531
1990-07-01	6924
1990-10-01	5565
1991-01-01	8202
1991-04-01	7219
1991-07-01	6427
1991-10-01	4535
1992-01-01	4613
1992-04-01	4643
1992-07-01	1551
1992-10-01	9855
1993-01-01	2162
1993-04-01	8723
1993-07-01	18785
1993-10-01	10772
1994-01-01	11096
1994-04-01	9194
1994-07-01	12025
1994-10-01	5249
1995-01-01	10149
1995-04-01	9796
1995-07-01	8582
1995-10-01	11904
1996-01-01	11756
1996-04-01	14795
1996-07-01	12665
1996-10-01	25828
1997-01-01	15028
1997-04-01	17344
1997-07-01	18564
1997-10-01	8452
1998-01-01	25151
1998-04-01	19911
1998-07-01	18174
1998-10-01	4259
1999-01-01	43020
1999-04-01	41782
1999-07-01	43166
1999-10-01	25677
2000-01-01	46796
2000-04-01	50046
2000-07-01	23879
2000-10-01	37955
2001-01-01	19565
2001-04-01	18516
2001-07-01	7273
2001-10-01	25720
2002-01-01	10867
2002-04-01	35460
2002-07-01	36462
2002-10-01	21026
2003-01-01	47964
2003-04-01	56610
2003-07-01	59938
2003-10-01	79255
2004-01-01	78425
2004-04-01	72994
2004-07-01	79914
2004-10-01	88094
2005-01-01	81461
2005-04-01	80719
2005-07-01	93586
2005-10-01	99839
2006-01-01	102037
2006-04-01	65017
2006-07-01	116896
2006-10-01	130039
2007-01-01	177780
2007-04-01	160557
2007-07-01	108694
2007-10-01	56342
2008-01-01	70365
2008-04-01	225545
2008-07-01	126626
2008-10-01	282867
2009-01-01	38595
2009-04-01	25913
2009-07-01	72626
2009-10-01	-47266
2010-01-01	50284
2010-04-01	-47339
2010-07-01	58698
2010-10-01	-102929
2011-01-01	37733
2011-04-01	33421
2011-07-01	-40941
2011-10-01	-50196
2012-01-01	77216
2012-04-01	-50905
2012-07-01	-44315
2012-10-01	-29838
2013-01-01	-24231
2013-04-01	-69533
2013-07-01	-24657
2013-10-01	11125
2014-01-01	-27159
2014-04-01	10079
2014-07-01	45774
2014-10-01	-20398
2015-01-01	11139
2015-04-01	14498
2015-07-01	-18738
2015-10-01	-38099
2016-01-01	28300
2016-04-01	-1840
2016-07-01	20811
2016-10-01	13021
2017-01-01	14239
2017-04-01	26444
2017-07-01	35946
2017-10-01	14064
2018-01-01	-10448
2018-04-01	47968