Quarter	Millions of US Dollars
1975-04-01	12
1975-10-01	19
1976-04-01	25
1976-10-01	12
1977-07-01	30
1981-01-01	75
1982-04-01	38
1982-07-01	-17
1982-10-01	-20
1983-04-01	-25
1983-10-01	-12
1984-07-01	-15
1985-10-01	75
1986-01-01	-75
1987-04-01	75
1987-10-01	75
1990-01-01	75
1991-04-01	20
1991-07-01	110
1992-01-01	39
1992-04-01	-50
1992-10-01	-75
1993-07-01	150
1993-10-01	-60
1994-01-01	88
1994-04-01	50
1994-07-01	50
1994-10-01	50
1995-01-01	-75
1995-04-01	0
1995-07-01	0
1995-10-01	-150
1996-01-01	-20
1996-04-01	250
1996-07-01	-230
1996-10-01	242
1997-01-01	81
1997-04-01	143
1997-07-01	600
1997-10-01	39
1998-01-01	-37
1998-04-01	500
1998-07-01	73
1998-10-01	15
1999-01-01	48
1999-04-01	442
1999-07-01	-38
1999-10-01	-54
2000-01-01	45
2000-04-01	890
2000-07-01	365
2000-10-01	86
2001-01-01	-269
2001-04-01	-279
2001-07-01	-5
2001-10-01	3767
2002-01-01	-96
2002-04-01	-28
2002-07-01	-659
2002-10-01	-21
2003-01-01	200
2003-04-01	26
2003-07-01	381
2003-10-01	2697
2004-01-01	104
2004-04-01	428
2004-07-01	-17
2004-10-01	901
2005-01-01	110
2005-04-01	101
2005-07-01	187
2005-10-01	-186
2006-01-01	5
2006-04-01	1667
2006-07-01	124
2006-10-01	396
2007-01-01	458
2007-04-01	1275
2007-07-01	55
2007-10-01	1035
2008-01-01	494
2008-04-01	48
2008-07-01	416
2008-10-01	-890
2009-01-01	-152
2009-04-01	581
2009-07-01	1553
2009-10-01	161
2010-01-01	303
2010-04-01	922
2010-07-01	214
2010-10-01	240
2011-01-01	598
2011-04-01	-312
2011-07-01	98
2011-10-01	-1869
2012-01-01	1407
2012-04-01	-631
2012-07-01	1376
2012-10-01	373
2013-01-01	1279
2013-04-01	-478
2013-07-01	286
2013-10-01	-664
2014-01-01	944
2014-04-01	631
2014-07-01	759
2014-10-01	-94
2015-01-01	534
2015-04-01	2224
2015-07-01	-293
2015-10-01	112
2016-01-01	-811
2016-04-01	-13
2016-07-01	-159
2016-10-01	-211
2017-01-01	18
2017-04-01	-92
2017-07-01	3770
2017-10-01	562
2018-01-01	-505
2018-04-01	1611