Quarter	Millions of US Dollars
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	19
1979-01-01	110
1979-04-01	111
1979-07-01	114
1979-10-01	110
1980-01-01	64
1980-04-01	127
1980-07-01	211
1980-10-01	188
1981-01-01	150
1981-04-01	356
1981-07-01	452
1981-10-01	561
1982-01-01	728
1982-04-01	528
1982-07-01	433
1982-10-01	538
1983-01-01	382
1983-04-01	357
1983-07-01	446
1983-10-01	302
1984-01-01	345
1984-04-01	296
1984-07-01	261
1984-10-01	541
1985-01-01	481
1985-04-01	619
1985-07-01	633
1985-10-01	510
1986-01-01	671
1986-04-01	633
1986-07-01	565
1986-10-01	622
1987-01-01	710
1987-04-01	899
1987-07-01	1431
1987-10-01	1577
1988-01-01	1490
1988-04-01	1230
1988-07-01	656
1988-10-01	397
1989-01-01	396
1989-04-01	364
1989-07-01	423
1989-10-01	504
1990-01-01	1359
1990-04-01	1310
1990-07-01	1260
1990-10-01	1292
1991-01-01	277
1991-04-01	676
1991-07-01	956
1991-10-01	924
1992-01-01	1157
1992-04-01	711
1992-07-01	939
1992-10-01	1007
1993-01-01	771
1993-04-01	844
1993-07-01	7198
1993-10-01	6794
1994-01-01	8508
1994-04-01	8664
1994-07-01	9486
1994-10-01	7751
1995-01-01	4549
1995-04-01	7729
1995-07-01	9916
1995-10-01	9890
1996-01-01	10199
1996-04-01	8269
1996-07-01	12158
1996-10-01	12703
1997-01-01	12460
1997-04-01	12581
1997-07-01	7796
1997-10-01	7112
1998-01-01	7271
1998-04-01	5476
1998-07-01	3972
1998-10-01	3846
1999-01-01	4203
1999-04-01	5896
1999-07-01	6469
1999-10-01	8175
2000-01-01	7998
2000-04-01	11975
2000-07-01	11282
2000-10-01	16331
2001-01-01	16996
2001-04-01	16601
2001-07-01	15843
2001-10-01	9384
2002-01-01	18290
2002-04-01	20671
2002-07-01	21870
2002-10-01	23992
2003-01-01	16187
2003-04-01	14606
2003-07-01	12009
2003-10-01	11902
2004-01-01	11174
2004-04-01	9153
2004-07-01	6970
2004-10-01	5865
2005-01-01	6891
2005-04-01	5631
2005-07-01	8211
2005-10-01	8267
2006-01-01	8381
2006-04-01	7891
2006-07-01	9289
2006-10-01	8982
2007-01-01	9763
2007-04-01	9595
2007-07-01	7403
2007-10-01	11964
2008-01-01	13907
2008-04-01	13038
2008-07-01	12881
2008-10-01	8488
2009-01-01	8784
2009-04-01	11668
2009-07-01	11017
2009-10-01	14209
2010-01-01	12225
2010-04-01	8095
2010-07-01	8795
2010-10-01	3441
2011-01-01	3494
2011-04-01	5153
2011-07-01	5118
2011-10-01	6090
2012-01-01	5036
2012-04-01	6118
2012-07-01	10599
2012-10-01	11653
2013-01-01	15707
2013-04-01	16625
2013-07-01	13952
2013-10-01	13227
2014-01-01	15313
2014-04-01	15542
2014-07-01	15055
2014-10-01	13705
2015-01-01	7145
2015-04-01	6637
2015-07-01	14890
2015-10-01	16881
2016-01-01	18664
2016-04-01	23597
2016-07-01	15625
2016-10-01	17953
2017-01-01	19862
2017-04-01	17011
2017-07-01	19789
2017-10-01	13685
2018-01-01	12253
2018-04-01	12360