Quarter	Millions of US Dollars
1975-01-01	0
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	0
1981-07-01	0
1981-10-01	0
1982-01-01	60
1982-04-01	100
1982-07-01	100
1982-10-01	100
1983-01-01	40
1996-01-01	0
1996-04-01	0
1996-07-01	0
1996-10-01	0
1997-01-01	0
1997-04-01	0
1997-07-01	0
1997-10-01	0
1998-01-01	0
1998-04-01	599
1998-07-01	609
1998-10-01	682
1999-01-01	748
1999-04-01	86
1999-07-01	88
1999-10-01	88
2000-01-01	50
2000-04-01	50
2000-07-01	50
2000-10-01	311
2001-01-01	239
2001-04-01	502
2001-07-01	531
2001-10-01	270
2002-01-01	268
2002-04-01	0
2002-07-01	0
2002-10-01	157
2003-01-01	163
2003-04-01	343
2003-07-01	350
2003-10-01	235
2004-01-01	229
2004-04-01	91
2004-07-01	91
2004-10-01	500
2005-01-01	480
2005-04-01	454
2005-07-01	453
2005-10-01	239
2006-01-01	243
2006-04-01	607
2006-07-01	612
2006-10-01	617
2007-01-01	625
2007-04-01	1018
2007-07-01	1067
2007-10-01	1383
2008-01-01	1449
2008-04-01	500
2008-07-01	500
2008-10-01	0
2009-01-01	0
2009-04-01	0
2009-07-01	1025
2009-10-01	1008
2010-01-01	944
2010-04-01	859
2010-07-01	0
2010-10-01	230
2011-01-01	253
2011-04-01	1262
2011-07-01	1173
2011-10-01	912
2012-01-01	941
2012-04-01	15
2012-07-01	19
2012-10-01	232
2013-01-01	313
2013-04-01	340
2013-07-01	349
2013-10-01	153
2014-01-01	1502
2014-04-01	2142
2014-07-01	1975
2014-10-01	1887
2015-01-01	561
2015-04-01	1699
2015-07-01	1714
2015-10-01	1665
2016-01-01	1729
2016-04-01	21
2016-07-01	8
2016-10-01	8
2017-01-01	0
2017-04-01	1717
2017-07-01	1791
2017-10-01	1831
2018-01-01	1907
2018-04-01	56