Quarter	Millions of US Dollars
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	75
1979-04-01	75
1979-07-01	75
1979-10-01	75
1980-01-01	50
1980-04-01	50
1980-07-01	50
1980-10-01	50
1981-01-01	0
1981-04-01	130
1981-07-01	132
1981-10-01	135
1982-01-01	284
1982-04-01	183
1982-07-01	178
1982-10-01	192
1983-01-01	41
1983-04-01	39
1983-07-01	38
1983-10-01	37
1984-01-01	116
1984-04-01	89
1984-07-01	123
1984-10-01	220
1985-01-01	157
1985-04-01	172
1985-07-01	144
1985-10-01	137
1986-01-01	205
1986-04-01	207
1986-07-01	212
1986-10-01	214
1987-01-01	159
1987-04-01	218
1987-07-01	394
1987-10-01	348
1988-01-01	335
1988-04-01	230
1988-07-01	53
1988-10-01	0
1989-01-01	0
1989-04-01	0
1989-07-01	0
1989-10-01	0
1990-01-01	0
1990-04-01	0
1990-07-01	0
1990-10-01	10
1991-01-01	10
1991-04-01	10
1991-07-01	10
1991-10-01	0
1992-01-01	0
1992-04-01	0
1992-07-01	0
1992-10-01	0
1993-01-01	0
1993-04-01	0
1993-07-01	461
1993-10-01	453
1994-01-01	519
1994-04-01	481
1994-07-01	935
1994-10-01	643
1995-01-01	330
1995-04-01	2654
1995-07-01	2730
1995-10-01	2726
1996-01-01	2923
1996-04-01	1072
1996-07-01	7334
1996-10-01	7469
1997-01-01	7286
1997-04-01	7294
1997-07-01	1189
1997-10-01	1156
1998-01-01	943
1998-04-01	908
1998-07-01	197
1998-10-01	27
1999-01-01	1027
1999-04-01	2577
1999-07-01	2755
1999-10-01	4797
2000-01-01	3786
2000-04-01	7674
2000-07-01	7377
2000-10-01	12069
2001-01-01	11376
2001-04-01	9354
2001-07-01	10417
2001-10-01	4143
2002-01-01	13919
2002-04-01	16806
2002-07-01	18345
2002-10-01	18799
2003-01-01	9095
2003-04-01	5469
2003-07-01	4246
2003-10-01	4611
2004-01-01	4103
2004-04-01	3672
2004-07-01	1970
2004-10-01	1788
2005-01-01	4507
2005-04-01	3933
2005-07-01	5215
2005-10-01	5190
2006-01-01	4465
2006-04-01	3657
2006-07-01	2328
2006-10-01	2309
2007-01-01	2415
2007-04-01	2717
2007-07-01	3256
2007-10-01	4192
2008-01-01	4699
2008-04-01	4892
2008-07-01	4198
2008-10-01	2977
2009-01-01	5019
2009-04-01	4675
2009-07-01	4771
2009-10-01	4726
2010-01-01	1546
2010-04-01	1546
2010-07-01	1546
2010-10-01	1546
2011-01-01	1262
2011-04-01	1561
2011-07-01	1539
2011-10-01	1528
2012-01-01	2022
2012-04-01	3177
2012-07-01	3216
2012-10-01	3246
2013-01-01	4750
2013-04-01	3761
2013-07-01	3761
2013-10-01	3761
2014-01-01	2468
2014-04-01	3237
2014-07-01	3141
2014-10-01	3079
2015-01-01	1003
2015-04-01	0
2015-07-01	4904
2015-10-01	4904
2016-01-01	5289
2016-04-01	8455
2016-07-01	4200
2016-10-01	6436
2017-01-01	6095
2017-04-01	3000
2017-07-01	3133
2017-10-01	133
2018-01-01	141
2018-04-01	550