Quarter	Millions of US Dollars
1997-10-01	2839527
1998-01-01	2905717
1998-04-01	2838530
1998-07-01	2984827
1998-10-01	3539802
1999-01-01	3541359
1999-04-01	3658507
1999-07-01	4239588
1999-10-01	4432964
2000-01-01	4519011
2000-04-01	4542615
2000-07-01	4414807
2000-10-01	4265702
2001-01-01	4111655
2001-04-01	4225853
2001-07-01	4336937
2001-10-01	3968926
2002-01-01	4013494
2002-04-01	4638660
2002-07-01	4535090
2002-10-01	4652903
2003-01-01	4841423
2003-04-01	4897050
2003-07-01	5261087
2003-10-01	5556045
2004-01-01	5955229
2004-04-01	5838445
2004-07-01	5781001
2004-10-01	6336163
2005-01-01	6292997
2005-04-01	6214028
2005-07-01	6017698
2005-10-01	5829682
2006-01-01	5821311
2006-04-01	5960981
2006-07-01	5867269
2006-10-01	5832507
2007-01-01	5903053
2007-04-01	5613458
2007-07-01	6056097
2007-10-01	6315144
2008-01-01	7283664
2008-04-01	6807023
2008-07-01	6833131
2008-10-01	8125132
2009-01-01	7419569
2009-04-01	7834644
2009-07-01	8461281
2009-10-01	8314565
2010-01-01	8336079
2010-04-01	9151994
2010-07-01	9871597
2010-10-01	10172935
2011-01-01	10026323
2011-04-01	10659091
2011-07-01	11434021
2011-10-01	11361380
2012-01-01	10735732
2012-04-01	11352365
2012-07-01	11778352
2012-10-01	10693837
2013-01-01	9869330
2013-04-01	9472485
2013-07-01	9725871
2013-10-01	9123297
2014-01-01	9352685
2014-04-01	9707079
2014-07-01	8993314
2014-10-01	8323572
2015-01-01	8435454
2015-04-01	8292396
2015-07-01	8462911
2015-10-01	8417842
2016-01-01	9313588
2016-04-01	10491254
2016-07-01	10550684
2016-10-01	9012678
2017-01-01	9412216
2017-04-01	9430284
2017-07-01	9438418
2017-10-01	9476937
2018-01-01	10048442