Quarter	Millions of US Dollars
2006-07-01	386
2006-10-01	429
2007-01-01	412
2007-04-01	424
2007-07-01	436
2007-10-01	440
2008-01-01	370
2008-04-01	1713
2008-07-01	1693
2008-10-01	1650
2009-01-01	1647
2009-04-01	1720
2009-07-01	3600
2009-10-01	3602
2010-01-01	3605
2010-04-01	3589
2010-07-01	3625
2010-10-01	3649
2011-01-01	3638
2011-04-01	3636
2011-07-01	3568
2011-10-01	3567
2012-01-01	3588
2012-04-01	5311
2012-07-01	5309
2012-10-01	5301
2013-01-01	3942
2013-04-01	5917
2013-07-01	5915
2013-10-01	5900
2014-01-01	5900
2014-04-01	6533
2014-07-01	6515
2014-10-01	6510
2015-01-01	6496
2015-04-01	6496
2015-07-01	6467
2015-10-01	6443
2016-01-01	6453
2016-04-01	6719
2016-07-01	6732
2016-10-01	6735
2017-01-01	6742
2017-04-01	6246
2017-07-01	6239
2017-10-01	6260
2018-01-01	6269
2018-04-01	6235