Quarter	Millions of US Dollars
1972-01-01	19
1972-04-01	35
1974-04-01	17
1974-07-01	30
1975-01-01	70
1975-04-01	101
1976-01-01	15
1976-04-01	10
1976-07-01	82
1976-10-01	80
1977-01-01	68
1977-04-01	86
1977-07-01	134
1979-01-01	-30
1979-04-01	71
1979-07-01	13
1979-10-01	31
1980-04-01	-25
1980-07-01	80
1981-01-01	4
1981-04-01	30
1981-10-01	151
1982-01-01	54
1982-04-01	-17
1982-07-01	75
1982-10-01	39
1983-01-01	150
1983-04-01	11
1983-07-01	-7
1983-10-01	196
1984-01-01	146
1984-04-01	65
1984-07-01	62
1984-10-01	58
1985-01-01	51
1985-04-01	155
1985-07-01	421
1985-10-01	94
1986-01-01	141
1986-04-01	-13
1986-07-01	166
1986-10-01	-75
1987-01-01	201
1987-04-01	52
1987-07-01	316
1987-10-01	200
1988-01-01	101
1988-04-01	52
1988-07-01	144
1988-10-01	593
1989-01-01	46
1989-04-01	491
1989-07-01	-32
1989-10-01	-134
1990-01-01	-81
1990-04-01	-99
1990-07-01	188
1990-10-01	371
1991-01-01	48
1991-04-01	510
1991-07-01	95
1991-10-01	76
1992-01-01	-76
1992-04-01	313
1992-07-01	-341
1992-10-01	-256
1993-01-01	-86
1993-04-01	-13
1993-07-01	1708
1993-10-01	364
1994-01-01	386
1994-04-01	-911
1994-07-01	-159
1994-10-01	-655
1995-01-01	379
1995-04-01	-138
1995-07-01	44
1995-10-01	809
1996-01-01	139
1996-04-01	-748
1996-07-01	-530
1996-10-01	1686
1997-01-01	189
1997-04-01	286
1997-07-01	302
1997-10-01	-285
1998-01-01	945
1998-04-01	1229
1998-07-01	-536
1998-10-01	-256
1999-01-01	891
1999-04-01	-417
1999-07-01	8
1999-10-01	-668
2000-01-01	-396
2000-04-01	430
2000-07-01	334
2000-10-01	-66
2001-01-01	111
2001-04-01	1404
2001-07-01	0
2001-10-01	-293
2002-01-01	-91
2002-04-01	1130
2002-07-01	482
2002-10-01	-256
2003-01-01	548
2003-04-01	118
2003-07-01	-381
2003-10-01	-399
2004-01-01	270
2004-04-01	-65
2004-07-01	800
2004-10-01	329
2005-01-01	-42
2005-04-01	240
2005-07-01	22
2005-10-01	-577
2006-01-01	-316
2006-04-01	465
2006-07-01	396
2006-10-01	89
2007-01-01	1577
2007-04-01	663
2007-07-01	-690
2007-10-01	387
2008-01-01	-386
2008-04-01	500
2008-07-01	1853
2008-10-01	16
2009-01-01	-209
2009-04-01	-984
2009-07-01	277
2009-10-01	1197
2010-01-01	1865
2010-04-01	-828
2010-07-01	2739
2010-10-01	2910
2011-01-01	2070
2011-04-01	3379
2011-07-01	799
2011-10-01	1762
2012-01-01	2466
2012-04-01	634
2012-07-01	1856
2012-10-01	1977
2013-01-01	4580
2013-04-01	-867
2013-07-01	2732
2013-10-01	1302
2014-01-01	1511
2014-04-01	1336
2014-07-01	2537
2014-10-01	1758
2015-01-01	4446
2015-04-01	5068
2015-07-01	-2300
2015-10-01	-612
2016-01-01	1693
2016-04-01	1049
2016-07-01	-888
2016-10-01	-246
2017-01-01	813
2017-04-01	-595
2017-07-01	1384
2017-10-01	-865
2018-01-01	-984
2018-04-01	380