Quarter	Millions of US Dollars
1971-01-01	0
1971-04-01	0
1971-07-01	0
1971-10-01	0
1972-01-01	0
1972-04-01	0
1972-07-01	0
1972-10-01	0
1973-01-01	0
1973-04-01	0
1973-07-01	0
1973-10-01	0
1974-01-01	0
1974-04-01	0
1974-07-01	0
1974-10-01	0
1975-01-01	0
1975-04-01	0
1975-07-01	0
1975-10-01	0
1976-01-01	0
1976-04-01	0
1976-07-01	0
1976-10-01	0
1977-01-01	0
1977-04-01	0
1977-07-01	0
1977-10-01	0
1978-01-01	0
1978-04-01	0
1978-07-01	0
1978-10-01	0
1979-01-01	0
1979-04-01	27
1979-07-01	29
1979-10-01	29
1980-01-01	26
1980-04-01	0
1980-07-01	0
1980-10-01	0
1981-01-01	0
1981-04-01	0
1981-07-01	0
1981-10-01	0
1982-01-01	0
1982-04-01	41
1982-07-01	40
1982-10-01	42
1983-01-01	41
1983-04-01	0
1983-07-01	0
1983-10-01	0
1984-01-01	0
1984-04-01	0
1984-07-01	0
1984-10-01	51
1985-01-01	57
1985-04-01	57
1985-07-01	140
1985-10-01	87
1986-01-01	86
1986-04-01	102
1986-07-01	62
1986-10-01	64
1987-01-01	69
1987-04-01	55
1987-07-01	0
1987-10-01	0
1988-01-01	0
1988-04-01	1
1988-07-01	1
1988-10-01	92
1989-01-01	89
1989-04-01	92
1989-07-01	152
1989-10-01	75
1990-01-01	72
1990-04-01	70
1990-07-01	89
1990-10-01	94
1991-01-01	82
1991-04-01	131
1991-07-01	78
1991-10-01	157
1992-01-01	342
1992-04-01	441
1992-07-01	933
1992-10-01	800
1993-01-01	595
1993-04-01	654
1993-07-01	390
1993-10-01	606
1994-01-01	610
1994-04-01	415
1994-07-01	405
1994-10-01	351
1995-01-01	363
1995-04-01	362
1995-07-01	187
1995-10-01	374
1996-01-01	552
1996-04-01	540
1996-07-01	618
1996-10-01	322
1997-01-01	138
1997-04-01	137
1997-07-01	241
1997-10-01	416
1998-01-01	405
1998-04-01	405
1998-07-01	397
1998-10-01	405
1999-01-01	399
1999-04-01	396
1999-07-01	398
1999-10-01	413
2000-01-01	410
2000-04-01	411
2000-07-01	596
2000-10-01	547
2001-01-01	539
2001-04-01	534
2001-07-01	540
2001-10-01	511
2002-01-01	509
2002-04-01	534
2002-07-01	622
2002-10-01	670
2003-01-01	670
2003-04-01	670
2003-07-01	490
2003-10-01	908
2004-01-01	917
2004-04-01	912
2004-07-01	911
2004-10-01	480
2005-01-01	930
2005-04-01	930
2005-07-01	680
2005-10-01	900
2006-01-01	450
2006-04-01	450
2006-07-01	874
2006-10-01	440
2007-01-01	444
2007-04-01	448
2007-07-01	0
2007-10-01	0
2008-01-01	353
2008-04-01	349
2008-07-01	319
2008-10-01	557
2009-01-01	240
2009-04-01	240
2009-07-01	240
2009-10-01	0
2010-01-01	170
2010-04-01	170
2010-07-01	170
2010-10-01	170
2011-01-01	0
2011-04-01	0
2011-07-01	0
2011-10-01	0
2012-01-01	0
2012-04-01	0
2012-07-01	0
2012-10-01	0
2013-01-01	0
2013-04-01	0
2013-07-01	0
2013-10-01	0
2014-01-01	0
2014-04-01	0
2014-07-01	0
2014-10-01	0
2015-01-01	0
2015-04-01	0
2015-07-01	0
2015-10-01	0
2016-01-01	650
2016-04-01	1530
2016-07-01	1530
2016-10-01	1530
2017-01-01	880
2017-04-01	1000
2017-07-01	1000
2017-10-01	1000
2018-01-01	1000
2018-04-01	1000