Quarter	Millions of US Dollars
1987-01-01	2418
1987-04-01	3086
1987-07-01	4127
1987-10-01	3917
1988-01-01	6679
1988-04-01	8117
1988-07-01	9231
1988-10-01	8969
1989-01-01	12356
1989-04-01	11263
1989-07-01	12838
1989-10-01	10160
1990-01-01	78089
1990-04-01	83321
1990-07-01	93957
1990-10-01	100522
1991-01-01	103946
1991-04-01	102492
1991-07-01	111465
1991-10-01	116665
1992-01-01	100691
1992-04-01	113724
1992-07-01	102088
1992-10-01	96212
1993-01-01	93833
1993-04-01	103499
1993-07-01	108848
1993-10-01	113293
1994-01-01	112008
1994-04-01	115073
1994-07-01	120975
1994-10-01	124274
1995-01-01	128469
1995-04-01	138919
1995-07-01	141198
1995-10-01	151550
1996-01-01	151147
1996-04-01	157294
1996-07-01	158894
1996-10-01	172835
1997-01-01	165502
1997-04-01	178829
1997-07-01	187376
1997-10-01	193074
1998-01-01	209345
1998-04-01	212250
1998-07-01	230250
1998-10-01	235248
1999-01-01	257669
1999-04-01	267495
1999-07-01	274014
1999-10-01	289357
2000-01-01	292843
2000-04-01	300671
2000-07-01	307425
2000-10-01	333438
2001-01-01	322995
2001-04-01	321821
2001-07-01	331675
2001-10-01	340126
2002-01-01	346028
2002-04-01	377763
2002-07-01	409138
2002-10-01	424704
2003-01-01	368801
2003-04-01	398328
2003-07-01	421608
2003-10-01	449699
2004-01-01	461603
2004-04-01	424949
2004-07-01	428182
2004-10-01	452363
2005-01-01	450887
2005-04-01	437764
2005-07-01	434815
2005-10-01	433186
2006-01-01	438173
2006-04-01	458066
2006-07-01	465255
2006-10-01	484368
2007-01-01	482598
2007-04-01	484248
2007-07-01	495061
2007-10-01	506188
2008-01-01	505279
2008-04-01	493365
2008-07-01	429446
2008-10-01	375495
2009-01-01	381124
2009-04-01	463073
2009-07-01	489548
2009-10-01	489189
2010-01-01	469998
2010-04-01	461145
2010-07-01	508238
2010-10-01	473112
2011-01-01	536637
2011-04-01	537066
2011-07-01	524160
2011-10-01	531451
2012-01-01	552822
2012-04-01	550145
2012-07-01	593801
2012-10-01	581381
2013-01-01	548269
2013-04-01	576678
2013-07-01	588848
2013-10-01	613715
2014-01-01	545663
2014-04-01	569954
2014-07-01	565888
2014-10-01	558717
2015-01-01	524575
2015-04-01	532526
2015-07-01	528180
2015-10-01	516090
2016-01-01	519343
2016-04-01	529621
2016-07-01	541243
2016-10-01	481240
2017-01-01	488517
2017-04-01	498877
2017-07-01	523209
2017-10-01	532662
2018-01-01	544569