Quarter	Millions of US Dollars
2006-01-01	-14
2006-04-01	1510
2006-07-01	-102
2006-10-01	2151
2007-01-01	-1056
2007-04-01	850
2007-07-01	737
2007-10-01	974
2008-01-01	1189
2008-04-01	2443
2008-07-01	1378
2008-10-01	-553
2009-01-01	610
2009-04-01	-2465
2009-07-01	1607
2009-10-01	245
2010-01-01	1290
2010-04-01	1071
2010-07-01	1042
2010-10-01	1851
2011-01-01	1520
2011-04-01	1233
2011-07-01	1031
2011-10-01	1910
2012-01-01	595
2012-04-01	-145
2012-07-01	1720
2012-10-01	1004
2013-01-01	125
2013-04-01	3016
2013-07-01	798
2013-10-01	2085
2014-01-01	1401
2014-04-01	-1750
2014-07-01	3886
2014-10-01	-91
2015-01-01	2128
2015-04-01	1961
2015-07-01	1585
2015-10-01	-275
2016-01-01	-1222
2016-04-01	125
2016-07-01	762
2016-10-01	114
2017-01-01	-131
2017-04-01	576
2017-07-01	1849
2017-10-01	631
2018-01-01	2372