Quarter	Millions of US Dollars
1972-04-01	20
1977-04-01	2
1985-10-01	-11
1987-04-01	-2
1994-10-01	30
1995-07-01	0
1995-10-01	-30
1996-01-01	60
1996-04-01	40
1996-07-01	-15
1996-10-01	-85
2002-07-01	170
2003-04-01	-2
2005-07-01	150
2006-07-01	100
2007-10-01	320
2011-10-01	408
2012-10-01	80
2013-10-01	-170
2014-10-01	-643
2016-04-01	575
2018-04-01	225