Quarter	Millions of US Dollars
1975-04-01	0
1975-07-01	0
1975-10-01	0
1976-01-01	0
1976-04-01	0
1976-07-01	0
1976-10-01	0
1977-01-01	0
1977-04-01	0
1977-07-01	0
1977-10-01	0
1978-01-01	0
1978-04-01	0
1978-07-01	0
1978-10-01	0
1979-01-01	0
1979-04-01	0
1979-07-01	0
1979-10-01	0
1980-01-01	0
1980-04-01	0
1980-07-01	0
1980-10-01	0
1981-01-01	0
1981-04-01	12
1981-07-01	30
1981-10-01	54
1982-01-01	51
1982-04-01	62
1982-07-01	45
1982-10-01	37
1983-01-01	37
1983-04-01	12
1983-07-01	27
1983-10-01	15
1984-01-01	15
1984-04-01	15
1984-07-01	0
1984-10-01	0
1985-01-01	75
1985-04-01	75
1985-07-01	75
1985-10-01	75
1986-01-01	0
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	50
1991-07-01	50
1991-10-01	125
1992-01-01	125
1992-04-01	75
1992-07-01	75
1992-10-01	0
1993-01-01	0
1993-04-01	0
1993-07-01	150
1993-10-01	90
1994-01-01	225
1994-04-01	225
1994-07-01	225
1994-10-01	225
1995-01-01	170
1995-04-01	170
1995-07-01	402
1995-10-01	302
1996-01-01	321
1996-04-01	321
1996-07-01	191
1996-10-01	143
1997-01-01	103
1997-04-01	104
1997-07-01	3
1997-10-01	34
1998-01-01	2
1998-04-01	60
1998-07-01	60
1998-10-01	77
1999-01-01	90
1999-04-01	198
1999-07-01	356
1999-10-01	225
2000-01-01	531
2000-04-01	1361
2000-07-01	1150
2000-10-01	1511
2001-01-01	1353
2001-04-01	783
2001-07-01	1326
2001-10-01	1127
2002-01-01	836
2002-04-01	1154
2002-07-01	516
2002-10-01	517
2003-01-01	517
2003-04-01	133
2003-07-01	52
2003-10-01	214
2004-01-01	221
2004-04-01	562
2004-07-01	1456
2004-10-01	1525
2005-01-01	1608
2005-04-01	1489
2005-07-01	600
2005-10-01	542
2006-01-01	690
2006-04-01	551
2006-07-01	580
2006-10-01	634
2007-01-01	757
2007-04-01	723
2007-07-01	752
2007-10-01	1346
2008-01-01	1037
2008-04-01	1259
2008-07-01	1188
2008-10-01	346
2009-01-01	311
2009-04-01	199
2009-07-01	1519
2009-10-01	1579
2010-01-01	1536
2010-04-01	2362
2010-07-01	1106
2010-10-01	3399
2011-01-01	4050
2011-04-01	3956
2011-07-01	3942
2011-10-01	2279
2012-01-01	1709
2012-04-01	2538
2012-07-01	3074
2012-10-01	4511
2013-01-01	4494
2013-04-01	3405
2013-07-01	3327
2013-10-01	1909
2014-01-01	2448
2014-04-01	2756
2014-07-01	2601
2014-10-01	3249
2015-01-01	3519
2015-04-01	4215
2015-07-01	4710
2015-10-01	3862
2016-01-01	3713
2016-04-01	3334
2016-07-01	2822
2016-10-01	2280
2017-01-01	3050
2017-04-01	2165
2017-07-01	1835
2017-10-01	2981
2018-01-01	3163
2018-04-01	3294