Quarter	Millions of US Dollars
1967-04-01	25
1968-04-01	30
1968-10-01	20
1969-10-01	50
1970-01-01	27
1971-01-01	56
1971-04-01	70
1972-10-01	50
1975-01-01	10
1975-04-01	10
1977-01-01	28
1977-04-01	87
1977-10-01	75
1978-01-01	26
1978-04-01	110
1979-01-01	36
1979-04-01	50
1979-07-01	100
1979-10-01	36
1980-01-01	200
1980-04-01	342
1980-07-01	279
1980-10-01	144
1981-01-01	250
1981-04-01	-2
1981-10-01	508
1982-01-01	822
1982-04-01	108
1982-07-01	100
1982-10-01	550
1983-01-01	127
1983-04-01	98
1983-07-01	164
1983-10-01	850
1984-01-01	334
1984-04-01	124
1984-07-01	602
1984-10-01	1249
1985-01-01	1050
1985-04-01	1607
1985-07-01	830
1985-10-01	665
1986-01-01	-260
1986-04-01	1288
1986-07-01	814
1986-10-01	-32
1987-01-01	32
1987-04-01	356
1987-07-01	140
1987-10-01	3234
1988-01-01	358
1988-04-01	717
1988-07-01	908
1988-10-01	-379
1989-01-01	-312
1989-04-01	422
1989-07-01	529
1989-10-01	-31
1990-01-01	16
1990-04-01	2714
1990-07-01	1791
1990-10-01	831
1991-01-01	5991
1991-04-01	-633
1991-07-01	224
1991-10-01	47
1992-01-01	1409
1992-04-01	1124
1992-07-01	-469
1992-10-01	-450
1993-01-01	2235
1993-04-01	1244
1993-07-01	7982
1993-10-01	861
1994-01-01	2009
1994-04-01	-68
1994-07-01	3736
1994-10-01	2624
1995-01-01	-1130
1995-04-01	6124
1995-07-01	1276
1995-10-01	1071
1996-01-01	-1160
1996-04-01	2793
1996-07-01	478
1996-10-01	1012
1997-01-01	943
1997-04-01	2453
1997-07-01	2382
1997-10-01	-783
1998-01-01	587
1998-04-01	3984
1998-07-01	48
1998-10-01	4267
1999-01-01	-1371
1999-04-01	9511
1999-07-01	-72
1999-10-01	12006
2000-01-01	10416
2000-04-01	14840
2000-07-01	9668
2000-10-01	8880
2001-01-01	11724
2001-04-01	9681
2001-07-01	5066
2001-10-01	19753
2002-01-01	9648
2002-04-01	5234
2002-07-01	8547
2002-10-01	14531
2003-01-01	22583
2003-04-01	10805
2003-07-01	8550
2003-10-01	15797
2004-01-01	30651
2004-04-01	30251
2004-07-01	9644
2004-10-01	25256
2005-01-01	25319
2005-04-01	29510
2005-07-01	-10705
2005-10-01	26892
2006-01-01	26185
2006-04-01	21867
2006-07-01	24046
2006-10-01	25693
2007-01-01	28207
2007-04-01	51831
2007-07-01	-6528
2007-10-01	7968
2008-01-01	24313
2008-04-01	32894
2008-07-01	-1647
2008-10-01	70902
2009-01-01	35776
2009-04-01	14837
2009-07-01	19321
2009-10-01	32288
2010-01-01	60
2010-04-01	-1672
2010-07-01	32420
2010-10-01	12786
2011-01-01	18555
2011-04-01	6885
2011-07-01	6136
2011-10-01	3517
2012-01-01	-30321
2012-04-01	-23914
2012-07-01	844
2012-10-01	-6408
2013-01-01	-18929
2013-04-01	3
2013-07-01	18010
2013-10-01	16678
2014-01-01	-7799
2014-04-01	4455
2014-07-01	-21642
2014-10-01	2521
2015-01-01	3333
2015-04-01	-2106
2015-07-01	-9411
2015-10-01	-4089
2016-01-01	-18142
2016-04-01	12096
2016-07-01	-9801
2016-10-01	1253
2017-01-01	8652
2017-04-01	11190
2017-07-01	3021
2017-10-01	5935
2018-01-01	4541
2018-04-01	5048