Quarter	Millions of US Dollars
1987-07-01	0
1987-10-01	0
1988-01-01	0
1988-04-01	0
1988-07-01	0
1989-10-01	0
1990-01-01	0
1990-04-01	0
1990-07-01	0
1990-10-01	0
1991-01-01	0
1991-04-01	0
1991-07-01	0
1991-10-01	0
1992-01-01	0
1992-04-01	0
1992-07-01	0
1992-10-01	0
1993-01-01	0
1993-04-01	0
1993-10-01	73
1994-01-01	221
1994-04-01	560
1994-07-01	405
1994-10-01	717
1995-01-01	298
1995-04-01	350
1995-07-01	589
1995-10-01	691
1996-01-01	757
1996-04-01	643
1996-07-01	234
1996-10-01	480
1997-01-01	372
1997-04-01	461
1997-07-01	521
1997-10-01	383
1998-01-01	411
1998-04-01	422
1998-07-01	374
1998-10-01	268
1999-01-01	186
1999-04-01	141
1999-07-01	124
1999-10-01	142
2000-01-01	118
2000-04-01	140
2000-07-01	156
2000-10-01	133
2001-01-01	161
2001-04-01	215
2001-07-01	226
2001-10-01	201
2002-01-01	129
2002-04-01	57
2002-07-01	41
2002-10-01	48
2003-01-01	50
2003-04-01	50
2003-07-01	59
2003-10-01	83
2004-01-01	72
2004-04-01	86
2004-07-01	63
2004-10-01	51
2005-01-01	37
2005-04-01	79
2005-07-01	79
2005-10-01	63
2006-01-01	56
2006-04-01	23
2006-07-01	27
2006-10-01	23
2007-01-01	21
2007-04-01	12
2007-07-01	15
2007-10-01	17
2008-01-01	16
2008-04-01	10
2008-07-01	9
2008-10-01	12
2009-01-01	9
2009-04-01	10
2009-07-01	8
2009-10-01	5
2010-01-01	1
2010-04-01	0
2010-07-01	200
2010-10-01	200
2011-01-01	200
2011-04-01	200
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	650
2017-01-01	650
2017-04-01	662
2017-07-01	662
2017-10-01	12
2018-01-01	13
2018-04-01	0