Quarter	Millions of US Dollars
1971-01-01	40
1971-04-01	80
1971-07-01	80
1971-10-01	80
1972-01-01	176
1972-04-01	274
1972-07-01	297
1972-10-01	319
1973-01-01	426
1973-04-01	469
1973-07-01	464
1973-10-01	434
1974-01-01	523
1974-04-01	545
1974-07-01	601
1974-10-01	769
1975-01-01	1233
1975-04-01	1471
1975-07-01	1627
1975-10-01	1975
1976-01-01	2528
1976-04-01	3039
1976-07-01	3372
1976-10-01	3624
1977-01-01	3769
1977-04-01	3908
1977-07-01	4029
1977-10-01	4729
1978-01-01	5124
1978-04-01	5325
1978-07-01	5837
1978-10-01	5858
1979-01-01	5905
1979-04-01	6289
1979-07-01	7038
1979-10-01	7333
1980-01-01	6589
1980-04-01	7710
1980-07-01	7750
1980-10-01	7817
1981-01-01	8017
1981-04-01	7593
1981-07-01	7763
1981-10-01	7919
1982-01-01	7756
1982-04-01	8091
1982-07-01	8374
1982-10-01	9624
1983-01-01	9999
1983-04-01	10061
1983-07-01	9932
1983-10-01	10151
1984-01-01	10841
1984-04-01	10686
1984-07-01	10724
1984-10-01	10623
1985-01-01	11132
1985-04-01	11571
1985-07-01	12675
1985-10-01	12919
1986-01-01	13614
1986-04-01	15019
1986-07-01	15412
1986-10-01	16256
1987-01-01	17357
1987-04-01	17307
1987-07-01	16997
1987-10-01	18809
1988-01-01	18692
1988-04-01	18342
1988-07-01	19700
1988-10-01	20702
1989-01-01	20090
1989-04-01	20675
1989-07-01	21701
1989-10-01	22595
1990-01-01	22422
1990-04-01	23143
1990-07-01	25683
1990-10-01	26484
1991-01-01	24719
1991-04-01	23905
1991-07-01	25682
1991-10-01	28508
1992-01-01	28488
1992-04-01	31076
1992-07-01	32811
1992-10-01	32245
1993-01-01	33733
1993-04-01	33633
1993-07-01	40286
1993-10-01	39041
1994-01-01	40716
1994-04-01	42198
1994-07-01	43501
1994-10-01	44926
1995-01-01	48991
1995-04-01	48942
1995-07-01	48571
1995-10-01	48512
1996-01-01	48283
1996-04-01	47636
1996-07-01	47846
1996-10-01	46977
1997-01-01	45264
1997-04-01	46440
1997-07-01	46298
1997-10-01	44145
1998-01-01	44315
1998-04-01	47486
1998-07-01	51275
1998-10-01	55321
1999-01-01	57670
1999-04-01	62632
1999-07-01	70135
1999-10-01	67959
2000-01-01	66344
2000-04-01	73831
2000-07-01	78626
2000-10-01	89751
2001-01-01	109939
2001-04-01	112099
2001-07-01	128288
2001-10-01	135179
2002-01-01	127131
2002-04-01	144191
2002-07-01	145357
2002-10-01	157039
2003-01-01	165424
2003-04-01	180147
2003-07-01	180989
2003-10-01	197349
2004-01-01	183871
2004-04-01	187625
2004-07-01	191971
2004-10-01	211029
2005-01-01	197195
2005-04-01	188526
2005-07-01	184393
2005-10-01	188080
2006-01-01	192519
2006-04-01	210145
2006-07-01	208283
2006-10-01	225999
2007-01-01	230233
2007-04-01	245206
2007-07-01	257761
2007-10-01	262643
2008-01-01	279842
2008-04-01	298518
2008-07-01	272387
2008-10-01	262670
2009-01-01	269421
2009-04-01	319356
2009-07-01	344599
2009-10-01	348129
2010-01-01	343122
2010-04-01	323759
2010-07-01	359525
2010-10-01	363602
2011-01-01	393687
2011-04-01	405341
2011-07-01	387576
2011-10-01	386607
2012-01-01	409888
2012-04-01	398080
2012-07-01	410280
2012-10-01	423737
2013-01-01	415251
2013-04-01	424942
2013-07-01	442036
2013-10-01	451420
2014-01-01	460919
2014-04-01	477167
2014-07-01	445389
2014-10-01	429789
2015-01-01	388990
2015-04-01	393734
2015-07-01	388995
2015-10-01	388380
2016-01-01	395614
2016-04-01	393827
2016-07-01	392858
2016-10-01	389780
2017-01-01	387429
2017-04-01	413626
2017-07-01	425449
2017-10-01	429607
2018-01-01	436876
2018-04-01	417682