Quarter	Millions of US Dollars
1975-04-01	16
1977-07-01	68
1978-01-01	87
1978-04-01	98
1978-10-01	81
1979-01-01	169
1979-04-01	179
1979-07-01	47
1979-10-01	87
1980-07-01	140
1980-10-01	25
1981-04-01	115
1981-07-01	85
1981-10-01	150
1982-01-01	100
1982-04-01	-16
1982-07-01	-25
1983-04-01	-30
1984-04-01	-66
1984-07-01	-34
1985-01-01	-46
1985-10-01	-62
1986-01-01	-93
1986-04-01	-92
1986-10-01	-157
1987-01-01	-100
1987-04-01	-103
1987-07-01	-16
1987-10-01	-25
1988-01-01	-18
1988-10-01	-70
1989-04-01	-23
1989-07-01	-124
1989-10-01	-112
1990-01-01	-15
1990-07-01	-168
1990-10-01	21
1991-04-01	65
1991-10-01	725
1992-01-01	75
1992-04-01	160
1992-07-01	520
1992-10-01	394
1993-01-01	439
1993-04-01	17461
1993-07-01	1081
1993-10-01	11825
1994-01-01	1394
1994-04-01	-22
1994-07-01	1237
1994-10-01	2497
1995-01-01	-980
1995-04-01	1876
1995-07-01	1797
1995-10-01	2643
1996-01-01	1935
1996-04-01	3849
1996-07-01	1843
1996-10-01	3595
1997-01-01	5297
1997-04-01	2219
1997-07-01	5909
1997-10-01	188
1998-01-01	3188
1998-04-01	6848
1998-07-01	1666
1998-10-01	-6297
1999-01-01	1690
1999-04-01	3854
1999-07-01	1830
1999-10-01	2699
2000-01-01	4887
2000-04-01	2960
2000-07-01	2585
2000-10-01	-1860
2001-01-01	1488
2001-04-01	4852
2001-07-01	-723
2001-10-01	-674
2002-01-01	-223
2002-04-01	-502
2002-07-01	-1265
2002-10-01	-265
2003-01-01	-1021
2003-04-01	-559
2003-07-01	-792
2003-10-01	-202
2004-01-01	-540
2004-04-01	-2787
2004-07-01	-1170
2004-10-01	198
2005-01-01	118
2005-04-01	-30598
2005-07-01	-228
2005-10-01	2
2006-01-01	170
2006-04-01	-211
2006-07-01	-216
2006-10-01	556
2007-01-01	-369
2007-04-01	495
2007-07-01	-825
2007-10-01	368
2008-01-01	-1691
2008-04-01	-1871
2008-07-01	-600
2008-10-01	-6599
2009-01-01	-790
2009-04-01	-922
2009-07-01	50
2009-10-01	73
2010-01-01	-289
2010-04-01	1025
2010-07-01	733
2010-10-01	743
2011-01-01	1315
2011-04-01	-142
2011-07-01	-319
2011-10-01	-63
2012-01-01	-270
2012-04-01	-279
2012-07-01	-67
2012-10-01	-85
2013-01-01	300
2013-04-01	193
2013-07-01	375
2013-10-01	-259
2014-01-01	-98
2014-04-01	1288
2014-07-01	68
2014-10-01	-918
2015-01-01	1529
2015-04-01	774
2015-07-01	42
2015-10-01	-740
2016-01-01	2620
2016-04-01	19606
2016-07-01	6058
2016-10-01	4890
2017-01-01	11992
2017-04-01	13699
2017-07-01	1951
2017-10-01	5936
2018-01-01	10333
2018-04-01	-2730