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	15
1981-04-01	15
1981-07-01	15
1981-10-01	15
1994-01-01	10
1994-04-01	10
1994-07-01	10
1994-10-01	20
1995-01-01	1
1995-04-01	14
1995-07-01	27
1995-10-01	18
1996-01-01	24
1996-04-01	26
1996-07-01	4
1996-10-01	21
1997-01-01	22
1997-04-01	24
1997-07-01	23
1997-10-01	22
1998-01-01	6
1998-04-01	1
2011-07-01	0
2011-10-01	0
2012-01-01	0
2012-04-01	0
2012-07-01	0
2012-10-01	0
2013-01-01	0
2013-04-01	0
2013-07-01	0
2013-10-01	0
2014-01-01	0
2014-04-01	0
2014-07-01	0
2014-10-01	0
2015-01-01	0
2015-04-01	0
2015-07-01	0
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	0