Quarter	Millions of US Dollars
1971-01-01	25
1973-01-01	30
1973-07-01	50
1974-04-01	52
1974-10-01	36
1975-04-01	34
1975-10-01	38
1976-07-01	20
1977-07-01	57
1978-04-01	83
1979-04-01	39
1979-07-01	31
1979-10-01	-43
1980-01-01	86
1980-10-01	95
1981-01-01	100
1981-04-01	100
1981-07-01	-72
1981-10-01	342
1982-01-01	200
1982-04-01	103
1982-07-01	90
1982-10-01	30
1983-01-01	275
1983-04-01	78
1983-07-01	34
1983-10-01	550
1984-01-01	67
1984-04-01	59
1984-07-01	349
1984-10-01	158
1985-01-01	398
1985-04-01	200
1985-07-01	142
1985-10-01	222
1986-01-01	395
1986-04-01	529
1986-07-01	1008
1986-10-01	97
1987-01-01	-202
1987-04-01	189
1987-07-01	-126
1987-10-01	-354
1988-01-01	122
1988-04-01	230
1988-07-01	-355
1988-10-01	-90
1989-01-01	-242
1989-04-01	254
1989-10-01	-54
1990-01-01	257
1990-04-01	249
1990-07-01	-163
1991-01-01	61
1991-04-01	558
1991-07-01	-86
1991-10-01	-56
1992-01-01	101
1992-04-01	-261
1992-07-01	372
1992-10-01	754
1993-01-01	1585
1993-04-01	-253
1993-07-01	39
1993-10-01	-207
1994-01-01	-611
1994-04-01	359
1994-07-01	-198
1994-10-01	-514
1995-01-01	205
1995-04-01	87
1995-07-01	1
1995-10-01	-211
1996-01-01	-935
1996-04-01	-370
1996-07-01	-119
1996-10-01	-91
1997-01-01	-302
1997-04-01	-401
1997-10-01	-388
1998-01-01	-30
1998-04-01	-191
1998-10-01	-267
1999-01-01	586
1999-04-01	-515
1999-07-01	-938
1999-10-01	777
2000-01-01	145
2000-04-01	561
2000-07-01	-2092
2000-10-01	214
2001-01-01	-457
2001-04-01	-703
2001-07-01	1451
2001-10-01	3457
2002-01-01	-880
2002-04-01	-716
2002-07-01	-1143
2002-10-01	572
2003-01-01	-689
2003-04-01	535
2003-07-01	-2109
2003-10-01	-1731
2004-01-01	-414
2004-04-01	-1315
2004-07-01	-647
2004-10-01	-225
2005-01-01	-52
2005-04-01	-147
2006-01-01	5
2006-04-01	-5
2007-04-01	967
2007-07-01	11081
2007-10-01	-11386
2008-01-01	6068
2008-04-01	493
2008-07-01	10375
2008-10-01	10159
2009-01-01	-3791
2009-04-01	3914
2009-07-01	-9535
2009-10-01	-6347
2010-01-01	5501
2010-04-01	847
2010-07-01	2258
2010-10-01	-4766
2011-01-01	-321
2011-04-01	-76
2011-07-01	85
2011-10-01	-265
2012-01-01	669
2012-04-01	323
2012-07-01	147
2012-10-01	84
2013-01-01	3449
2013-04-01	425
2013-07-01	-1369
2013-10-01	-336
2014-01-01	5233
2014-04-01	-225
2014-07-01	1356
2014-10-01	845
2015-01-01	806
2015-04-01	-687
2015-07-01	-141
2015-10-01	-1590
2016-01-01	1443
2016-04-01	-595
2016-07-01	994
2016-10-01	-2430
2017-01-01	1467
2017-04-01	2368
2017-07-01	-1086
2017-10-01	-4480
2018-01-01	3170
2018-04-01	60