Quarter	Millions of US Dollars
1977-04-01	8
1982-04-01	-10
1985-04-01	10
1994-10-01	191
1995-01-01	5766
1997-04-01	500
1998-10-01	-269
2000-01-01	-23
2000-07-01	3750
2001-01-01	-472
2001-04-01	-3143
2002-04-01	-28
2002-10-01	-3
2003-04-01	-2
2004-10-01	-2
2005-01-01	187
2005-10-01	650
2006-04-01	-740
2009-01-01	-32
2009-04-01	-2908
2009-07-01	-131
2010-01-01	-131
2010-04-01	-71
2010-07-01	-131
2011-07-01	-650
2012-01-01	-182
2012-10-01	-68
2013-07-01	-581
2014-01-01	-194
2014-04-01	2000
2014-10-01	-382
2015-01-01	746
2015-04-01	740
2015-10-01	-650
2016-07-01	2000
2016-10-01	750
2017-01-01	1000
2017-04-01	3000
2017-10-01	2500
2018-01-01	3000