Quarter	Millions of US Dollars
1972-04-01	32
1972-10-01	20
1973-10-01	30
1975-04-01	12
1975-10-01	19
1976-04-01	25
1976-07-01	60
1976-10-01	71
1977-01-01	62
1977-07-01	30
1977-10-01	62
1978-01-01	25
1979-01-01	25
1981-01-01	75
1981-07-01	-30
1981-10-01	-25
1982-04-01	-4
1982-07-01	58
1982-10-01	-20
1983-01-01	-67
1983-04-01	-25
1983-10-01	58
1984-07-01	-15
1985-01-01	4
1985-04-01	-25
1985-10-01	42
1986-01-01	-86
1986-10-01	155
1987-01-01	50
1987-04-01	75
1987-10-01	73
1988-10-01	-80
1989-01-01	-25
1989-07-01	-68
1989-10-01	-200
1990-01-01	68
1991-01-01	35
1991-04-01	20
1991-07-01	50
1992-01-01	39
1992-04-01	-50
1992-10-01	-75
1993-07-01	216
1993-10-01	173
1994-01-01	246
1994-04-01	66
1994-07-01	49
1994-10-01	50
1995-01-01	-79
1995-04-01	30
1995-07-01	10
1995-10-01	-120
1996-01-01	-22
1996-04-01	609
1996-07-01	141
1996-10-01	1306
1997-01-01	550
1997-04-01	667
1997-07-01	775
1997-10-01	-81
1998-01-01	-97
1998-04-01	2491
1998-07-01	113
1998-10-01	24
1999-01-01	861
1999-04-01	-225
1999-07-01	1201
1999-10-01	928
2000-01-01	285
2000-04-01	3086
2000-07-01	464
2000-10-01	487
2001-01-01	1491
2001-04-01	113
2001-07-01	2004
2001-10-01	2794
2002-01-01	248
2002-04-01	-1421
2002-07-01	-195
2002-10-01	185
2003-01-01	285
2003-04-01	1262
2003-07-01	1391
2003-10-01	3483
2004-01-01	1256
2004-04-01	1949
2004-07-01	972
2004-10-01	3356
2005-01-01	592
2005-04-01	34
2005-07-01	2518
2005-10-01	647
2006-01-01	-879
2006-04-01	3458
2006-07-01	1278
2006-10-01	174
2007-01-01	-480
2007-04-01	3395
2007-07-01	791
2007-10-01	427
2008-01-01	832
2008-04-01	1425
2008-07-01	1603
2008-10-01	-1474
2009-01-01	-1819
2009-04-01	-2667
2009-07-01	1781
2009-10-01	2321
2010-01-01	1533
2010-04-01	-1352
2010-07-01	3690
2010-10-01	409
2011-01-01	2897
2011-04-01	3438
2011-07-01	1481
2011-10-01	1686
2012-01-01	6322
2012-04-01	-2211
2012-07-01	5912
2012-10-01	4059
2013-01-01	4742
2013-04-01	4022
2013-07-01	5770
2013-10-01	1973
2014-01-01	380
2014-04-01	3436
2014-07-01	5073
2014-10-01	-5849
2015-01-01	-2706
2015-04-01	2615
2015-07-01	-4752
2015-10-01	-1164
2016-01-01	2181
2016-04-01	-3199
2016-07-01	2426
2016-10-01	-2925
2017-01-01	3529
2017-04-01	1864
2017-07-01	8952
2017-10-01	705
2018-01-01	12035
2018-04-01	11114