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	100
1992-07-01	100
1992-10-01	100
1993-01-01	147
1993-04-01	49
1993-07-01	147
1993-10-01	143
1994-01-01	349
1994-04-01	363
1994-07-01	738
1994-10-01	737
1995-01-01	464
1995-04-01	464
1995-07-01	1035
1995-10-01	1061
1996-01-01	998
1996-04-01	1017
1996-07-01	0
1996-10-01	25
1997-01-01	94
1997-04-01	129
1997-07-01	129
1997-10-01	469
1998-01-01	47
1998-04-01	247
1998-07-01	201
1998-10-01	320
1999-01-01	320
1999-04-01	501
1999-07-01	850
1999-10-01	631
2000-01-01	781
2000-04-01	1003
2000-07-01	611
2000-10-01	1640
2001-01-01	1465
2001-04-01	1300
2001-07-01	1300
2001-10-01	400
2002-01-01	560
2002-04-01	1746
2002-07-01	1742
2002-10-01	1666
2003-01-01	2786
2003-04-01	1169
2003-07-01	1192
2003-10-01	1939
2004-01-01	1414
2004-04-01	1687
2004-07-01	4979
2004-10-01	4717
2005-01-01	4280
2005-04-01	4842
2005-07-01	2007
2005-10-01	2847
2006-01-01	3311
2006-04-01	6329
2006-07-01	6780
2006-10-01	6447
2007-01-01	6216
2007-04-01	2901
2007-07-01	2789
2007-10-01	2259
2008-01-01	2987
2008-04-01	3467
2008-07-01	5039
2008-10-01	6644
2009-01-01	8908
2009-04-01	10181
2009-07-01	9511
2009-10-01	8177
2010-01-01	5635
2010-04-01	4893
2010-07-01	6652
2010-10-01	8560
2011-01-01	8817
2011-04-01	10204
2011-07-01	7765
2011-10-01	5756
2012-01-01	7228
2012-04-01	6187
2012-07-01	8547
2012-10-01	9507
2013-01-01	20847
2013-04-01	19692
2013-07-01	17301
2013-10-01	16318
2014-01-01	2912
2014-04-01	4786
2014-07-01	7199
2014-10-01	8598
2015-01-01	9914
2015-04-01	9186
2015-07-01	7401
2015-10-01	6864
2016-01-01	8272
2016-04-01	14620
2016-07-01	15015
2016-10-01	16000
2017-01-01	18013
2017-04-01	15167
2017-07-01	21053
2017-10-01	21838
2018-01-01	18881
2018-04-01	18969