Quarter	Millions of US Dollars
1986-04-01	0
1986-07-01	0
1986-10-01	0
1987-01-01	0
1987-04-01	0
1987-07-01	0
1987-10-01	0
1988-01-01	0
1988-04-01	0
1988-07-01	0
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	0
1991-01-01	0
1991-04-01	0
1991-07-01	0
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	0
1993-10-01	0
1994-01-01	0
1994-04-01	494
1994-07-01	659
1994-10-01	1198
1995-01-01	1288
1995-04-01	1413
1995-07-01	1683
1995-10-01	1798
1996-01-01	2253
1996-04-01	1820
1996-07-01	1581
1996-10-01	1367
1997-01-01	840
1997-04-01	943
1997-07-01	1983
1997-10-01	4424
1998-01-01	3973
1998-04-01	4966
1998-07-01	4542
1998-10-01	2222
1999-01-01	3786
1999-04-01	2657
1999-07-01	2802
1999-10-01	3778
2000-01-01	2905
2000-04-01	4135
2000-07-01	3608
2000-10-01	5177
2001-01-01	4821
2001-04-01	6562
2001-07-01	6739
2001-10-01	7606
2002-01-01	7448
2002-04-01	8459
2002-07-01	9051
2002-10-01	7518
2003-01-01	9804
2003-04-01	6663
2003-07-01	7443
2003-10-01	7797
2004-01-01	7615
2004-04-01	7679
2004-07-01	10724
2004-10-01	11853
2005-01-01	8452
2005-04-01	9313
2005-07-01	6457
2005-10-01	7109
2006-01-01	6921
2006-04-01	8526
2006-07-01	8377
2006-10-01	6425
2007-01-01	10023
2007-04-01	7633
2007-07-01	6694
2007-10-01	7312
2008-01-01	7487
2008-04-01	9225
2008-07-01	11269
2008-10-01	10743
2009-01-01	9479
2009-04-01	8688
2009-07-01	9435
2009-10-01	10382
2010-01-01	11038
2010-04-01	10656
2010-07-01	8815
2010-10-01	9980
2011-01-01	8401
2011-04-01	8694
2011-07-01	11586
2011-10-01	11340
2012-01-01	20352
2012-04-01	18517
2012-07-01	15536
2012-10-01	12231
2013-01-01	23511
2013-04-01	28164
2013-07-01	31939
2013-10-01	34502
2014-01-01	20178
2014-04-01	18481
2014-07-01	16601
2014-10-01	34394
2015-01-01	32395
2015-04-01	30717
2015-07-01	33529
2015-10-01	13822
2016-01-01	14478
2016-04-01	16875
2016-07-01	16343
2016-10-01	16020
2017-01-01	16771
2017-04-01	23866
2017-07-01	24829
2017-10-01	27736
2018-01-01	30455
2018-04-01	21886