Quarter	Millions of US Dollars
1973-10-01	2
1980-04-01	30
1981-04-01	20
1981-10-01	136
1982-04-01	30
1984-04-01	1
1984-07-01	21
1984-10-01	40
1985-01-01	150
1985-07-01	21
1985-10-01	167
1986-01-01	294
1986-04-01	0
1986-10-01	45
1987-01-01	153
1987-10-01	113
1988-04-01	203
1988-07-01	341
1988-10-01	12
1989-04-01	250
1989-10-01	338
1990-01-01	125
1990-07-01	149
1990-10-01	230
1991-01-01	152
1991-04-01	-36
1991-07-01	-37
1991-10-01	-6
1992-01-01	-150
1992-10-01	-181
1993-01-01	-401
1993-04-01	-136
1993-07-01	146
1993-10-01	265
1994-01-01	170
1994-04-01	135
1994-07-01	279
1994-10-01	-431
1995-01-01	-2
1995-07-01	202
1995-10-01	131
1996-01-01	315
1996-04-01	73
1996-07-01	450
1996-10-01	134
1997-01-01	294
1997-04-01	436
1997-07-01	913
1997-10-01	80
1998-04-01	-114
1998-07-01	-208
1999-01-01	50
1999-04-01	-401
1999-07-01	-224
1999-10-01	-405
2000-01-01	-309
2000-04-01	-110
2001-01-01	-190
2001-04-01	-109
2001-07-01	-150
2002-01-01	-150
2002-04-01	100
2002-07-01	-392
2002-10-01	-73
2003-01-01	-220
2003-07-01	100
2003-10-01	99
2004-01-01	798
2004-04-01	500
2004-07-01	273
2004-10-01	848
2005-01-01	752
2005-04-01	525
2005-07-01	1198
2005-10-01	672
2006-01-01	2733
2006-04-01	2215
2006-07-01	805
2006-10-01	1366
2007-01-01	4740
2007-04-01	2121
2007-07-01	1594
2007-10-01	3024
2008-01-01	311
2008-04-01	159
2008-07-01	-99
2008-10-01	618
2009-01-01	-687
2009-04-01	-787
2009-07-01	572
2009-10-01	2203
2010-01-01	-262
2010-04-01	-162
2010-07-01	-1208
2010-10-01	-583
2011-01-01	-933
2011-04-01	-1246
2011-07-01	1261
2011-10-01	-1510
2012-01-01	-2983
2012-04-01	-2171
2012-07-01	-1456
2012-10-01	41
2013-01-01	1170
2013-04-01	1342
2013-07-01	1000
2014-01-01	624
2014-04-01	1932
2014-07-01	2516
2014-10-01	-257
2015-01-01	1039
2015-04-01	2488
2015-07-01	800
2015-10-01	-200
2016-01-01	-307
2016-04-01	-675
2016-07-01	3665
2016-10-01	1006
2017-01-01	1879
2017-04-01	1269
2017-07-01	1020
2017-10-01	2572
2018-01-01	2185
2018-04-01	-1012