Quarter	Millions of US Dollars
1999-01-01	5186
1999-04-01	5391
1999-07-01	5325
1999-10-01	6168
2000-01-01	6802
2000-04-01	6852
2000-07-01	7260
2000-10-01	7003
2001-01-01	6892
2001-04-01	7566
2001-07-01	7475
2001-10-01	7519
2002-01-01	7671
2002-04-01	7886
2002-07-01	7700
2002-10-01	7789
2003-01-01	7688
2003-04-01	8017
2003-07-01	8077
2003-10-01	8403
2004-01-01	8606
2004-04-01	9537
2004-07-01	10138
2004-10-01	10905
2005-01-01	12351
2005-04-01	14216
2005-07-01	14998
2005-10-01	15123
2006-01-01	15996
2006-04-01	17540
2006-07-01	19386
2006-10-01	20526
2007-01-01	22775
2007-04-01	27791
2007-07-01	30713
2007-10-01	34016
2008-01-01	37854
2008-04-01	42740
2008-07-01	37577
2008-10-01	28830
2009-01-01	30082
2009-04-01	36908
2009-07-01	40628
2009-10-01	41453
2010-01-01	43599
2010-04-01	42892
2010-07-01	47983
2010-10-01	50006
2011-01-01	51407
2011-04-01	50468
2011-07-01	45256
2011-10-01	42861
2012-01-01	45968
2012-04-01	40759
2012-07-01	42956
2012-10-01	46400
2013-01-01	48556
2013-04-01	49894
2013-07-01	52532
2013-10-01	53139
2014-01-01	53734
2014-04-01	55921
2014-07-01	53524
2014-10-01	48829
2015-01-01	48430
2015-04-01	49804
2015-07-01	48496
2015-10-01	48592
2016-01-01	50066
2016-04-01	50850
2016-07-01	55468
2016-10-01	54640
2017-01-01	58971
2017-04-01	63229
2017-07-01	64273
2017-10-01	66128
2018-01-01	68252