Quarter	Millions of US Dollars
1988-04-01	33075
1988-07-01	35773
1988-10-01	37752
1989-01-01	37305
1989-04-01	34690
1989-07-01	36964
1989-10-01	38674
1990-01-01	38761
1990-04-01	40479
1990-07-01	42905
1990-10-01	40542
1991-01-01	41635
1991-04-01	40367
1991-07-01	41196
1991-10-01	39486
1992-01-01	39640
1992-04-01	40621
1992-07-01	39250
1992-10-01	37913
1993-01-01	37188
1993-04-01	35532
1993-07-01	31518
1993-10-01	32378
1994-01-01	32670
1994-04-01	31574
1994-07-01	35536
1994-10-01	36516
1995-01-01	34713
1995-04-01	34108
1995-07-01	34517
1995-10-01	33924
1996-01-01	36292
1996-04-01	37742
1996-07-01	40894
1996-10-01	42695
1997-01-01	40717
1997-04-01	40728
1997-07-01	39788
1997-10-01	39719
1998-01-01	41234
1998-04-01	39111
1998-07-01	37807
1998-10-01	37943
1999-01-01	42436
1999-04-01	42949
1999-07-01	43140
1999-10-01	44475
2000-01-01	46421
2000-04-01	50584
2000-07-01	47667
2000-10-01	51237
2001-01-01	47336
2001-04-01	47681
2001-07-01	48813
2001-10-01	50057
2002-01-01	52538
2002-04-01	56497
2002-07-01	54855
2002-10-01	59920
2003-01-01	62710
2003-04-01	71413
2003-07-01	69013
2003-10-01	73775
2004-01-01	73143
2004-04-01	70339
2004-07-01	74194
2004-10-01	78804
2005-01-01	81349
2005-04-01	82724
2005-07-01	81146
2005-10-01	82397
2006-01-01	80986
2006-04-01	88605
2006-07-01	94379
2006-10-01	96165
2007-01-01	99239
2007-04-01	97726
2007-07-01	103263
2007-10-01	100261
2008-01-01	106282
2008-04-01	114538
2008-07-01	103775
2008-10-01	98988
2009-01-01	104701
2009-04-01	123020
2009-07-01	131675
2009-10-01	137438
2010-01-01	138963
2010-04-01	134329
2010-07-01	154818
2010-10-01	155105
2011-01-01	161956
2011-04-01	169990
2011-07-01	167099
2011-10-01	179149
2012-01-01	195855
2012-04-01	194389
2012-07-01	209601
2012-10-01	216505
2013-01-01	220097
2013-04-01	207056
2013-07-01	220696
2013-10-01	220229
2014-01-01	222056
2014-04-01	222486
2014-07-01	214756
2014-10-01	202794
2015-01-01	197706
2015-04-01	208500
2015-07-01	199010
2015-10-01	206824
2016-01-01	217776
2016-04-01	209997
2016-07-01	208033
2016-10-01	199836
2017-01-01	197096
2017-04-01	205362
2017-07-01	205406
2017-10-01	202305
2018-01-01	201872