Quarter	Millions of US Dollars
1972-10-01	50
1974-04-01	17
1976-07-01	367
1976-10-01	11
1977-01-01	38
1977-04-01	37
1977-07-01	44
1978-01-01	114
1978-07-01	26
1978-10-01	76
1979-01-01	30
1979-04-01	28
1979-07-01	100
1980-07-01	71
1981-10-01	55
1982-01-01	30
1983-01-01	-17
1984-01-01	-21
1984-07-01	-34
1985-01-01	-31
1985-10-01	-57
1986-01-01	-16
1986-07-01	-100
1986-10-01	-84
1987-04-01	-70
1987-07-01	-12
1988-01-01	-106
1988-07-01	-32
1988-10-01	-50
1989-01-01	-55
1989-07-01	-70
1990-04-01	837
1990-07-01	-83
1991-10-01	-116
1992-01-01	-207
1992-10-01	3348
1993-01-01	150
1993-07-01	305
1993-10-01	714
1994-01-01	138
1994-04-01	405
1994-07-01	280
1994-10-01	329
1995-04-01	14
1995-07-01	548
1995-10-01	262
1996-01-01	-33
1996-04-01	890
1996-07-01	942
1996-10-01	1926
1997-01-01	1114
1997-04-01	1048
1997-07-01	1210
1997-10-01	-309
1998-01-01	732
1998-04-01	711
1998-07-01	-488
1998-10-01	-521
1999-01-01	1195
1999-04-01	754
1999-07-01	1037
1999-10-01	363
2000-01-01	1576
2000-04-01	-409
2000-07-01	103
2000-10-01	-448
2001-01-01	-902
2001-04-01	260
2001-07-01	-206
2001-10-01	1012
2002-01-01	1641
2002-04-01	827
2002-07-01	345
2002-10-01	830
2003-01-01	1208
2003-04-01	801
2003-07-01	497
2003-10-01	1121
2004-01-01	283
2004-04-01	143
2004-07-01	968
2004-10-01	-166
2005-01-01	1351
2005-04-01	684
2005-07-01	943
2005-10-01	-1117
2006-01-01	2421
2006-04-01	-718
2006-07-01	1501
2006-10-01	-873
2007-01-01	1103
2007-04-01	-128
2007-07-01	-416
2007-10-01	-418
2008-01-01	343
2008-04-01	-1032
2008-07-01	154
2008-10-01	-275
2009-01-01	505
2009-04-01	834
2009-07-01	1235
2009-10-01	1730
2010-01-01	1002
2010-04-01	-29
2010-07-01	1341
2010-10-01	1098
2011-01-01	2001
2011-04-01	1075
2011-07-01	-500
2011-10-01	-950
2012-01-01	2287
2012-04-01	349
2012-07-01	-241
2012-10-01	1143
2013-01-01	178
2013-04-01	1350
2013-07-01	-391
2013-10-01	500
2014-01-01	-200
2014-04-01	719
2014-07-01	-372
2015-01-01	2564
2015-04-01	167
2015-07-01	446
2015-10-01	221
2016-01-01	700
2016-04-01	-650
2016-10-01	-468
2017-01-01	-832
2017-04-01	-17
2017-07-01	1300
2017-10-01	-618
2018-01-01	3661
2018-04-01	298