Quarter	Millions of US Dollars
1977-04-01	8
1978-04-01	62
1982-04-01	-10
1985-04-01	10
1988-04-01	-62
1993-07-01	5
1993-10-01	10
1994-01-01	10
1994-04-01	10
1994-07-01	9
1994-10-01	200
1995-01-01	5754
1995-04-01	13
1995-07-01	10
1995-10-01	15
1996-01-01	28
1996-04-01	-1
1996-07-01	47
1996-10-01	116
1997-01-01	-18
1997-04-01	614
1997-07-01	19
1997-10-01	-73
1998-01-01	1
1998-04-01	-75
1998-07-01	-44
1998-10-01	-322
1999-01-01	-22
2000-01-01	-23
2000-07-01	3750
2001-01-01	-472
2001-04-01	-3143
2002-04-01	-147
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	3315
2017-10-01	2800
2018-01-01	3000