Quarter	Millions of US Dollars
1998-10-01	4742
1999-01-01	4862
1999-04-01	4563
1999-07-01	4697
1999-10-01	4306
2000-01-01	4642
2000-04-01	4593
2000-07-01	4131
2000-10-01	4021
2001-01-01	4051
2001-04-01	4388
2001-07-01	4333
2001-10-01	4443
2002-01-01	4763
2002-04-01	5574
2002-07-01	5596
2002-10-01	6773
2003-01-01	7071
2003-04-01	7432
2003-07-01	7223
2003-10-01	7888
2004-01-01	7792
2004-04-01	7742
2004-07-01	8062
2004-10-01	9026
2005-01-01	9369
2005-04-01	8073
2005-07-01	8237
2005-10-01	8152
2006-01-01	8363
2006-04-01	9167
2006-07-01	9381
2006-10-01	9839
2007-01-01	11171
2007-04-01	10231
2007-07-01	10391
2007-10-01	10780
2008-01-01	12992
2008-04-01	12151
2008-07-01	10870
2008-10-01	10598
2009-01-01	11737
2009-04-01	14745
2009-07-01	17318
2009-10-01	16876
2010-01-01	17053
2010-04-01	15478
2010-07-01	17185
2010-10-01	16817
2011-01-01	21608
2011-04-01	21268
2011-07-01	19878
2011-10-01	20239
2012-01-01	20326
2012-04-01	19352
2012-07-01	19781
2012-10-01	22309
2013-01-01	21555
2013-04-01	25568
2013-07-01	26071
2013-10-01	31367
2014-01-01	35022
2014-04-01	35707
2014-07-01	32830
2014-10-01	33065
2015-01-01	30086
2015-04-01	30899
2015-07-01	32780
2015-10-01	31521
2016-01-01	33355
2016-04-01	32303
2016-07-01	32986
2016-10-01	29549
2017-01-01	31343
2017-04-01	33953
2017-07-01	35448
2017-10-01	33698
2018-01-01	36113