Quarter	Millions of US Dollars
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	48
1981-04-01	42
1981-07-01	43
1981-10-01	44
2007-07-01	0
2007-10-01	0
2008-01-01	0
2008-04-01	0
2008-07-01	0
2008-10-01	0
2009-01-01	0
2009-04-01	0
2009-07-01	0
2009-10-01	0
2010-01-01	0
2010-04-01	0
2010-07-01	0
2010-10-01	0
2011-01-01	0
2011-04-01	0
2011-07-01	1000
2011-10-01	1000
2012-01-01	1000
2012-04-01	2770
2012-07-01	1770
2012-10-01	1770
2013-01-01	1770
2013-04-01	3000
2013-07-01	3000
2013-10-01	3000
2014-01-01	3000
2014-04-01	0
2014-07-01	0
2014-10-01	500
2015-01-01	500
2015-04-01	500
2015-07-01	500
2015-10-01	0
2016-01-01	0
2016-04-01	0
2016-07-01	0
2016-10-01	0
2017-01-01	0
2017-04-01	0
2017-07-01	0
2017-10-01	0
2018-01-01	0
2018-04-01	2946