Quarter	Millions of US Dollars
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	0
1979-07-01	0
1979-10-01	0
1980-01-01	0
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	0
1982-07-01	0
1982-10-01	0
1983-01-01	0
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	7
1985-01-01	507
1985-04-01	507
1985-07-01	507
1985-10-01	500
1986-01-01	1
1986-04-01	1
1986-07-01	1
1986-10-01	1
1987-01-01	0
1987-04-01	0
1987-07-01	0
1987-10-01	1000
1988-01-01	2126
1988-04-01	2741
1988-07-01	2705
1988-10-01	3795
1989-01-01	2553
1989-04-01	1785
1989-07-01	1851
1989-10-01	1719
1990-01-01	1924
1990-04-01	2138
1990-07-01	2207
1990-10-01	522
1991-01-01	1382
1991-04-01	1187
1991-07-01	1230
1991-10-01	1441
1992-01-01	272
1992-04-01	284
1992-07-01	1297
1992-10-01	1046
1993-01-01	1046
1993-04-01	1046
1993-07-01	47
1993-10-01	1547
1994-01-01	1545
1994-04-01	1546
1994-07-01	1557
1994-10-01	1057
1995-01-01	1205
1995-04-01	3712
1995-07-01	3701
1995-10-01	2709
1996-01-01	2553
1996-04-01	1555
1996-07-01	3112
1996-10-01	4184
1997-01-01	7013
1997-04-01	5955
1997-07-01	7201
1997-10-01	6190
1998-01-01	8949
1998-04-01	8492
1998-07-01	9808
1998-10-01	10044
1999-01-01	4203
1999-04-01	5616
1999-07-01	3637
1999-10-01	3619
2000-01-01	7715
2000-04-01	14360
2000-07-01	12103
2000-10-01	11244
2001-01-01	7698
2001-04-01	10790
2001-07-01	8673
2001-10-01	8055
2002-01-01	7841
2002-04-01	5345
2002-07-01	8655
2002-10-01	10486
2003-01-01	14661
2003-04-01	14702
2003-07-01	10361
2003-10-01	6493
2004-01-01	10717
2004-04-01	13937
2004-07-01	11979
2004-10-01	12069
2005-01-01	14434
2005-04-01	11232
2005-07-01	11997
2005-10-01	20851
2006-01-01	17069
2006-04-01	15800
2006-07-01	20690
2006-10-01	10709
2007-01-01	12016
2007-04-01	19947
2007-07-01	36082
2007-10-01	33935
2008-01-01	38208
2008-04-01	31841
2008-07-01	6940
2008-10-01	4814
2009-01-01	7556
2009-04-01	7137
2009-07-01	5362
2009-10-01	3912
2010-01-01	8084
2010-04-01	8155
2010-07-01	15062
2010-10-01	9103
2011-01-01	7223
2011-04-01	8806
2011-07-01	8595
2011-10-01	7560
2012-01-01	9109
2012-04-01	7614
2012-07-01	9346
2012-10-01	5920
2013-01-01	5068
2013-04-01	3811
2013-07-01	8574
2013-10-01	9366
2014-01-01	18593
2014-04-01	19984
2014-07-01	12361
2014-10-01	17252
2015-01-01	9616
2015-04-01	8475
2015-07-01	14948
2015-10-01	10435
2016-01-01	9721
2016-04-01	11546
2016-07-01	5419
2016-10-01	9167
2017-01-01	10511
2017-04-01	9414
2017-07-01	9713
2017-10-01	5242
2018-01-01	2895
2018-04-01	3760