Quarter	Millions of US Dollars
1997-10-01	14102
1998-01-01	14072
1998-04-01	14416
1998-07-01	14830
1998-10-01	16599
1999-01-01	16498
1999-04-01	18352
1999-07-01	19148
1999-10-01	19111
2000-01-01	19245
2000-04-01	18941
2000-07-01	17494
2000-10-01	19027
2001-01-01	18482
2001-04-01	20644
2001-07-01	21790
2001-10-01	23010
2002-01-01	24717
2002-04-01	28344
2002-07-01	29856
2002-10-01	34641
2003-01-01	38493
2003-04-01	38030
2003-07-01	42741
2003-10-01	44669
2004-01-01	48295
2004-04-01	49205
2004-07-01	53311
2004-10-01	61214
2005-01-01	62837
2005-04-01	60917
2005-07-01	61566
2005-10-01	58737
2006-01-01	62550
2006-04-01	61611
2006-07-01	64962
2006-10-01	72973
2007-01-01	78386
2007-04-01	81241
2007-07-01	84676
2007-10-01	87851
2008-01-01	92590
2008-04-01	101819
2008-07-01	92045
2008-10-01	81463
2009-01-01	66834
2009-04-01	75092
2009-07-01	82926
2009-10-01	80990
2010-01-01	81769
2010-04-01	69022
2010-07-01	80183
2010-10-01	75434
2011-01-01	90492
2011-04-01	85637
2011-07-01	76223
2011-10-01	63837
2012-01-01	72186
2012-04-01	72154
2012-07-01	79619
2012-10-01	82134
2013-01-01	80528
2013-04-01	85807
2013-07-01	90361
2013-10-01	92989
2014-01-01	97715
2014-04-01	101602
2014-07-01	93675
2014-10-01	91145
2015-01-01	88279
2015-04-01	87397
2015-07-01	90454
2015-10-01	85424
2016-01-01	93731
2016-04-01	90625
2016-07-01	94728
2016-10-01	89120
2017-01-01	93416
2017-04-01	99434
2017-07-01	104291
2017-10-01	107287
2018-01-01	111604