Quarter	Millions of US Dollars
1976-04-01	10
1976-10-01	35
1977-01-01	28
1978-01-01	25
1978-07-01	66
1979-07-01	22
1980-01-01	22
1985-10-01	-23
1986-07-01	-8
1986-10-01	-34
1987-01-01	-27
1987-07-01	-14
1988-01-01	-25
1988-07-01	-39
1988-10-01	-3
1989-07-01	-5
1990-01-01	-25
1996-07-01	290
1996-10-01	100
1999-04-01	152
2001-10-01	-100
2002-01-01	0
2002-07-01	-225
2003-07-01	465
2004-04-01	-167
2007-04-01	671
2008-07-01	-601
2010-10-01	1347
2012-10-01	1500
2013-10-01	600
2014-04-01	2904
2014-07-01	74
2015-04-01	1000
2015-07-01	152
2016-01-01	-65
2016-10-01	313
2017-04-01	-551