Quarter	Millions of US Dollars
2002-01-01	13651
2002-04-01	11482
2002-07-01	8692
2002-10-01	11307
2003-01-01	11552
2003-04-01	11925
2003-07-01	11526
2003-10-01	10901
2004-01-01	10525
2004-04-01	9291
2004-07-01	11508
2004-10-01	12423
2005-01-01	13389
2005-04-01	16094
2005-07-01	18784
2005-10-01	18374
2006-01-01	20494
2006-04-01	21059
2006-07-01	24402
2006-10-01	28380
2007-01-01	31201
2007-04-01	35193
2007-07-01	40044
2007-10-01	44081
2008-01-01	47718
2008-04-01	58158
2008-07-01	55282
2008-10-01	49410
2009-01-01	48872
2009-04-01	58518
2009-07-01	67166
2009-10-01	75585
2010-01-01	78556
2010-04-01	85329
2010-07-01	97461
2010-10-01	108417
2011-01-01	114540
2011-04-01	127891
2011-07-01	112695
2011-10-01	122795
2012-01-01	136572
2012-04-01	128854
2012-07-01	139601
2012-10-01	148926
2013-01-01	154052
2013-04-01	146073
2013-07-01	148149
2013-10-01	147024
2014-01-01	160153
2014-04-01	171473
2014-07-01	156241
2014-10-01	151330
2015-01-01	127118
2015-04-01	127571
2015-07-01	99972
2015-10-01	101536
2016-01-01	112002
2016-04-01	118465
2016-07-01	115699
2016-10-01	120417
2017-01-01	123987
2017-04-01	118578
2017-07-01	127019
2017-10-01	130382
2018-01-01	132758