Quarter	Millions of US Dollars
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	0
1982-04-01	0
1982-07-01	0
1982-10-01	0
1983-01-01	0
1983-04-01	0
1983-07-01	0
1983-10-01	0
1984-01-01	0
1984-04-01	0
1984-07-01	0
1984-10-01	0
1985-01-01	0
1985-04-01	23
1985-07-01	24
1985-10-01	24
1986-01-01	24
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	0
1991-07-01	0
1991-10-01	0
1992-01-01	0
1992-04-01	20
1992-07-01	21
1992-10-01	19
1993-01-01	19
1993-04-01	0
1993-07-01	0
1993-10-01	0
1994-01-01	0
1994-04-01	16
1994-07-01	16
1994-10-01	16
1995-01-01	18
1995-04-01	36
1995-07-01	35
1995-10-01	35
1996-01-01	34
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	6
1998-04-01	106
1998-07-01	106
1998-10-01	115
1999-01-01	131
1999-04-01	89
1999-07-01	239
1999-10-01	242
2000-01-01	402
2000-04-01	435
2000-07-01	312
2000-10-01	294
2001-01-01	129
2001-04-01	87
2001-07-01	58
2001-10-01	46
2002-01-01	205
2002-04-01	25
2002-07-01	39
2002-10-01	35
2003-01-01	103
2003-04-01	227
2003-07-01	277
2003-10-01	380
2004-01-01	395
2004-04-01	632
2004-07-01	908
2004-10-01	1791
2005-01-01	1858
2005-04-01	1769
2005-07-01	1238
2005-10-01	1070
2006-01-01	1306
2006-04-01	1653
2006-07-01	1395
2006-10-01	2312
2007-01-01	1898
2007-04-01	1652
2007-07-01	1909
2007-10-01	674
2008-01-01	1495
2008-04-01	1553
2008-07-01	2302
2008-10-01	3430
2009-01-01	2890
2009-04-01	2543
2009-07-01	1886
2009-10-01	1083
2010-01-01	1053
2010-04-01	1771
2010-07-01	2354
2010-10-01	2804
2011-01-01	2915
2011-04-01	4438
2011-07-01	3459
2011-10-01	3685
2012-01-01	5482
2012-04-01	4148
2012-07-01	6073
2012-10-01	5553
2013-01-01	4820
2013-04-01	5284
2013-07-01	5921
2013-10-01	5589
2014-01-01	4431
2014-04-01	4300
2014-07-01	1837
2014-10-01	4013
2015-01-01	5095
2015-04-01	5902
2015-07-01	6603
2015-10-01	4672
2016-01-01	5029
2016-04-01	6804
2016-07-01	7333
2016-10-01	8682
2017-01-01	9867
2017-04-01	12001
2017-07-01	12288
2017-10-01	12785
2018-01-01	10012
2018-04-01	9010