Quarter	Millions of US Dollars
1975-07-01	19
1976-01-01	28
1983-01-01	-28
1985-07-01	-18
1993-07-01	110
1994-10-01	71
1995-01-01	-4
1995-04-01	11
1995-07-01	8
1995-10-01	-5
1996-01-01	-2
1996-04-01	-79
1996-07-01	0
1996-10-01	47
1997-01-01	-65
1997-04-01	110
1997-07-01	107
1997-10-01	-1
1998-01-01	47
1998-04-01	542
1998-07-01	659
1998-10-01	-19
1999-01-01	573
1999-04-01	-728
1999-07-01	-149
1999-10-01	-4
2000-01-01	233
2000-04-01	131
2000-07-01	-37
2000-10-01	-104
2001-01-01	65
2001-04-01	-61
2001-07-01	-34
2001-10-01	0
2002-01-01	-38
2002-04-01	22
2002-07-01	125
2002-10-01	-115
2003-01-01	126
2003-04-01	-237
2003-07-01	-1
2003-10-01	126
2004-01-01	-16
2004-04-01	1512
2004-07-01	-135
2004-10-01	23
2005-01-01	-178
2005-04-01	1
2005-07-01	-557
2005-10-01	669
2006-01-01	-310
2006-04-01	-3
2006-07-01	0
2006-10-01	-612
2007-01-01	215
2007-04-01	14
2007-07-01	-13
2007-10-01	-8
2008-01-01	7
2008-04-01	-62
2008-07-01	29
2008-10-01	100
2009-01-01	-273
2009-04-01	-20
2009-07-01	422
2009-10-01	834
2010-01-01	32
2010-04-01	499
2010-07-01	-3
2010-10-01	1437
2011-01-01	-18
2011-04-01	297
2011-07-01	0
2011-10-01	-11
2012-01-01	493
2012-04-01	486
2012-07-01	822
2012-10-01	240
2013-01-01	275
2013-04-01	420
2013-07-01	-23
2013-10-01	1374
2014-01-01	-3
2014-04-01	-366
2014-07-01	285
2014-10-01	97
2015-01-01	199
2015-04-01	1353
2015-07-01	72
2015-10-01	-24
2016-01-01	-158
2016-04-01	32
2016-07-01	-76
2016-10-01	-15
2017-01-01	10
2017-04-01	-51
2017-07-01	376
2017-10-01	-494
2018-01-01	950
2018-04-01	2301