Quarter	Millions of US Dollars
1997-10-01	26442
1998-01-01	26833
1998-04-01	27048
1998-07-01	28110
1998-10-01	31014
1999-01-01	28560
1999-04-01	29589
1999-07-01	30190
1999-10-01	29687
2000-01-01	29051
2000-04-01	28744
2000-07-01	27399
2000-10-01	28928
2001-01-01	28427
2001-04-01	30463
2001-07-01	31608
2001-10-01	31976
2002-01-01	32140
2002-04-01	35880
2002-07-01	37233
2002-10-01	43062
2003-01-01	46925
2003-04-01	46811
2003-07-01	52048
2003-10-01	55139
2004-01-01	57781
2004-04-01	59048
2004-07-01	63603
2004-10-01	73468
2005-01-01	74504
2005-04-01	72026
2005-07-01	72608
2005-10-01	70793
2006-01-01	75258
2006-04-01	73969
2006-07-01	79181
2006-10-01	89603
2007-01-01	103321
2007-04-01	104646
2007-07-01	110969
2007-10-01	112377
2008-01-01	120398
2008-04-01	133364
2008-07-01	120729
2008-10-01	109782
2009-01-01	92472
2009-04-01	110273
2009-07-01	123543
2009-10-01	121245
2010-01-01	124972
2010-04-01	104492
2010-07-01	121888
2010-10-01	110888
2011-01-01	135310
2011-04-01	132842
2011-07-01	114893
2011-10-01	94536
2012-01-01	106806
2012-04-01	105365
2012-07-01	114084
2012-10-01	116611
2013-01-01	116543
2013-04-01	122663
2013-07-01	127491
2013-10-01	134742
2014-01-01	137889
2014-04-01	139181
2014-07-01	108976
2014-10-01	106070
2015-01-01	101856
2015-04-01	101848
2015-07-01	104800
2015-10-01	98852
2016-01-01	107006
2016-04-01	103392
2016-07-01	106594
2016-10-01	100192
2017-01-01	105587
2017-04-01	110641
2017-07-01	115661
2017-10-01	118717
2018-01-01	123082