Quarter	Millions of US Dollars
1971-01-01	10
1972-04-01	26
1974-01-01	5
1975-07-01	19
1977-01-01	20
1977-07-01	24
1978-07-01	17
1979-01-01	29
1979-07-01	466
1979-10-01	225
1980-04-01	9
1980-10-01	9
1981-01-01	52
1981-04-01	4
1981-07-01	-24
1981-10-01	-8
1983-07-01	40
1983-10-01	4
1984-01-01	-20
1984-07-01	-49
1984-10-01	81
1985-01-01	-7
1985-04-01	-43
1985-07-01	27
1985-10-01	-5
1986-01-01	50
1986-04-01	9
1986-07-01	150
1986-10-01	100
1987-01-01	103
1987-04-01	-21
1987-07-01	-71
1987-10-01	91
1988-01-01	25
1988-04-01	17
1988-10-01	-5
1989-07-01	-360
1989-10-01	-220
1990-07-01	-75
1990-10-01	-90
1991-01-01	-50
1991-04-01	-8
1991-10-01	-84
1992-01-01	-226
1992-07-01	-38
1992-10-01	-104
1993-04-01	165
1993-07-01	-95
1994-04-01	40
1994-07-01	69
1994-10-01	9
1995-01-01	721
1995-04-01	-2
1995-07-01	276
1995-10-01	304
1996-01-01	0
1996-04-01	-85
1996-07-01	96
1996-10-01	37
1997-01-01	-26
1997-04-01	139
1997-07-01	292
1997-10-01	-58
1998-01-01	78
1998-04-01	-366
1998-07-01	7
1998-10-01	574
1999-01-01	-310
1999-04-01	-117
1999-10-01	-51
2000-01-01	-54
2000-04-01	108
2000-07-01	-89
2001-01-01	55
2001-04-01	70
2001-07-01	598
2001-10-01	455
2002-01-01	41
2002-04-01	112
2002-07-01	467
2002-10-01	-24
2003-01-01	189
2003-04-01	811
2003-07-01	248
2003-10-01	1897
2004-01-01	943
2004-04-01	1932
2004-07-01	-175
2004-10-01	683
2005-01-01	87
2005-04-01	-507
2005-07-01	-51
2005-10-01	1592
2006-01-01	689
2006-04-01	460
2006-07-01	-1373
2006-10-01	2828
2007-01-01	84
2007-04-01	1735
2007-07-01	-2679
2007-10-01	-1289
2008-01-01	-465
2008-04-01	330
2008-07-01	-150
2008-10-01	-1256
2009-01-01	2976
2009-04-01	3234
2009-07-01	534
2009-10-01	2251
2010-01-01	-415
2010-04-01	1503
2010-10-01	232
2011-01-01	1103
2011-04-01	3146
2011-07-01	260
2011-10-01	-1466
2012-01-01	1084
2012-04-01	1033
2012-07-01	3502
2012-10-01	388
2013-01-01	4756
2013-04-01	713
2013-07-01	3315
2013-10-01	1640
2014-01-01	1276
2014-04-01	443
2014-07-01	69
2014-10-01	-325
2015-01-01	100
2015-04-01	2028
2015-07-01	-412
2015-10-01	2861
2016-01-01	11640
2016-04-01	-972
2016-07-01	-260
2016-10-01	-854
2017-01-01	-1437
2017-04-01	1864
2017-07-01	-191
2017-10-01	-1227
2018-01-01	2312
2018-04-01	-2339