Quarter	Millions of US Dollars
1988-04-01	87915
1988-07-01	92012
1988-10-01	101873
1989-01-01	106668
1989-04-01	107065
1989-07-01	116398
1989-10-01	119054
1990-01-01	116336
1990-04-01	124199
1990-07-01	134496
1990-10-01	125617
1991-01-01	132830
1991-04-01	131095
1991-07-01	134235
1991-10-01	128662
1992-01-01	131393
1992-04-01	130467
1992-07-01	124953
1992-10-01	118024
1993-01-01	118588
1993-04-01	111526
1993-07-01	109165
1993-10-01	111966
1994-01-01	119712
1994-04-01	124029
1994-07-01	122546
1994-10-01	126893
1995-01-01	125725
1995-04-01	125986
1995-07-01	141761
1995-10-01	145694
1996-01-01	160039
1996-04-01	167699
1996-07-01	174941
1996-10-01	181466
1997-01-01	181438
1997-04-01	180351
1997-07-01	183867
1997-10-01	171032
1998-01-01	175396
1998-04-01	174500
1998-07-01	177528
1998-10-01	187429
1999-01-01	201405
1999-04-01	212650
1999-07-01	223130
1999-10-01	235344
2000-01-01	227610
2000-04-01	230983
2000-07-01	219355
2000-10-01	225668
2001-01-01	210985
2001-04-01	220695
2001-07-01	224509
2001-10-01	235492
2002-01-01	250882
2002-04-01	268060
2002-07-01	271735
2002-10-01	281192
2003-01-01	303750
2003-04-01	347308
2003-07-01	368395
2003-10-01	425490
2004-01-01	460346
2004-04-01	440313
2004-07-01	481824
2004-10-01	536783
2005-01-01	544443
2005-04-01	554222
2005-07-01	560926
2005-10-01	573479
2006-01-01	593116
2006-04-01	645600
2006-07-01	673648
2006-10-01	739131
2007-01-01	780487
2007-04-01	859586
2007-07-01	968095
2007-10-01	1003749
2008-01-01	1102236
2008-04-01	1186079
2008-07-01	1012304
2008-10-01	899275
2009-01-01	871824
2009-04-01	1007870
2009-07-01	1080368
2009-10-01	1122688
2010-01-01	1115190
2010-04-01	1041471
2010-07-01	1151293
2010-10-01	1206115
2011-01-01	1211888
2011-04-01	1255491
2011-07-01	1181351
2011-10-01	1202005
2012-01-01	1260673
2012-04-01	1233346
2012-07-01	1261706
2012-10-01	1239098
2013-01-01	1225147
2013-04-01	1143699
2013-07-01	1144470
2013-10-01	1127061
2014-01-01	1169468
2014-04-01	1224219
2014-07-01	1160355
2014-10-01	1140117
2015-01-01	1080575
2015-04-01	1101080
2015-07-01	1029677
2015-10-01	1071713
2016-01-01	1115034
2016-04-01	1092367
2016-07-01	1104245
2016-10-01	1038122
2017-01-01	1086329
2017-04-01	1087112
2017-07-01	1111118
2017-10-01	1121895
2018-01-01	1140021