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	16
1981-07-01	16
1981-10-01	16
1982-01-01	16
1982-04-01	0
1982-07-01	0
1982-10-01	0
1983-01-01	0
1983-04-01	67
1983-07-01	104
1983-10-01	103
1984-01-01	163
1984-04-01	90
1984-07-01	50
1984-10-01	99
1985-01-01	51
1985-04-01	94
1985-07-01	108
1985-10-01	99
1986-01-01	109
1986-04-01	81
1986-07-01	102
1986-10-01	46
1987-01-01	66
1987-04-01	33
1987-07-01	16
1987-10-01	42
1988-01-01	21
1988-04-01	44
1988-07-01	83
1988-10-01	196
1989-01-01	183
1989-04-01	150
1989-07-01	281
1989-10-01	164
1990-01-01	154
1990-04-01	160
1991-10-01	0
1992-01-01	0
1992-04-01	0
1992-07-01	0
1992-10-01	500
1993-01-01	500
1993-04-01	650
1993-07-01	650
1993-10-01	150
1994-01-01	500
1994-04-01	456
1994-07-01	446
1994-10-01	446
1995-01-01	139
1995-04-01	81
1995-07-01	317
1995-10-01	865
1996-01-01	750
1996-04-01	727
1996-07-01	1142
1996-10-01	2334
1997-01-01	2359
1997-04-01	2599
1997-07-01	1782
1997-10-01	8608
1998-01-01	8619
1998-04-01	8966
1998-07-01	9692
1998-10-01	2476
1999-01-01	2255
1999-04-01	3477
1999-07-01	4584
1999-10-01	4270
2000-01-01	6938
2000-04-01	26364
2000-07-01	26766
2000-10-01	27534
2001-01-01	26674
2001-04-01	2565
2001-07-01	2136
2001-10-01	986
2002-01-01	1703
2002-04-01	1660
2002-07-01	1434
2002-10-01	1769
2003-01-01	1890
2003-04-01	5681
2003-07-01	7707
2003-10-01	8576
2004-01-01	8071
2004-04-01	45548
2004-07-01	44390
2004-10-01	45332
2005-01-01	43226
2005-04-01	1312
2005-07-01	1235
2005-10-01	1376
2006-01-01	2271
2006-04-01	2556
2006-07-01	3117
2006-10-01	2973
2007-01-01	3283
2007-04-01	2880
2007-07-01	2299
2007-10-01	8451
2008-01-01	7114
2008-04-01	7377
2008-07-01	7151
2008-10-01	1298
2009-01-01	1899
2009-04-01	1659
2009-07-01	2200
2009-10-01	2125
2010-01-01	1434
2010-04-01	1300
2010-07-01	1797
2010-10-01	1308
2011-01-01	2067
2011-04-01	1620
2011-07-01	723
2011-10-01	805
2012-01-01	85
2012-04-01	85
2012-07-01	85
2012-10-01	0
2013-01-01	0
2013-04-01	0
2013-07-01	0
2013-10-01	576
2014-01-01	576
2014-04-01	1840
2014-07-01	1840
2014-10-01	2330
2015-01-01	2331
2015-04-01	1095
2015-07-01	1170
2015-10-01	117
2016-01-01	1643
2016-04-01	18635
2016-07-01	19157
2016-10-01	19157
2017-01-01	17834
2017-04-01	3176
2017-07-01	3055
2017-10-01	3055
2018-01-01	3144
2018-04-01	4797