Quarter	Millions of US Dollars
1971-10-01	31
1972-01-01	113
1972-04-01	153
1972-07-01	173
1972-10-01	208
1973-01-01	277
1973-04-01	289
1973-07-01	340
1973-10-01	395
1974-01-01	401
1974-04-01	398
1974-07-01	392
1974-10-01	449
1975-01-01	585
1975-04-01	662
1975-07-01	669
1975-10-01	732
1976-01-01	800
1976-04-01	943
1976-07-01	1049
1976-10-01	1137
1977-01-01	1254
1977-04-01	1578
1977-07-01	2067
1977-10-01	2683
1978-01-01	3243
1978-04-01	3371
1978-07-01	3716
1978-10-01	3838
1979-01-01	3810
1979-04-01	3825
1979-07-01	4118
1979-10-01	4091
1980-01-01	3801
1980-04-01	4253
1980-07-01	4239
1980-10-01	4181
1981-01-01	4114
1981-04-01	4448
1981-07-01	4898
1981-10-01	5806
1982-01-01	6266
1982-04-01	6299
1982-07-01	6324
1982-10-01	6378
1983-01-01	6109
1983-04-01	5970
1983-07-01	5871
1983-10-01	5668
1984-01-01	5673
1984-04-01	5490
1984-07-01	5239
1984-10-01	5162
1985-01-01	5117
1985-04-01	5095
1985-07-01	5123
1985-10-01	4889
1986-01-01	4974
1986-04-01	4910
1986-07-01	4870
1986-10-01	4525
1987-01-01	4687
1987-04-01	4357
1987-07-01	4457
1987-10-01	4354
1988-01-01	4067
1988-04-01	3542
1988-07-01	2952
1988-10-01	2588
1989-01-01	2348
1989-04-01	2266
1989-07-01	2205
1989-10-01	2123
1990-01-01	37475
1990-04-01	38209
1990-07-01	39651
1990-10-01	40498
1991-01-01	39222
1991-04-01	40112
1991-07-01	41310
1991-10-01	43314
1992-01-01	42422
1992-04-01	43029
1992-07-01	44947
1992-10-01	47060
1993-01-01	48070
1993-04-01	51362
1993-07-01	51325
1993-10-01	52891
1994-01-01	57774
1994-04-01	59286
1994-07-01	60927
1994-10-01	59616
1995-01-01	56836
1995-04-01	56494
1995-07-01	58859
1995-10-01	59703
1996-01-01	62256
1996-04-01	62308
1996-07-01	69331
1996-10-01	69748
1997-01-01	71432
1997-04-01	76831
1997-07-01	72857
1997-10-01	72347
1998-01-01	73780
1998-04-01	73598
1998-07-01	74830
1998-10-01	74830
1999-01-01	73947
1999-04-01	77895
1999-07-01	79077
1999-10-01	79815
2000-01-01	82246
2000-04-01	81758
2000-07-01	81863
2000-10-01	79583
2001-01-01	83921
2001-04-01	79388
2001-07-01	81514
2001-10-01	75163
2002-01-01	74834
2002-04-01	71407
2002-07-01	70916
2002-10-01	72436
2003-01-01	64530
2003-04-01	61783
2003-07-01	58127
2003-10-01	59971
2004-01-01	60880
2004-04-01	59839
2004-07-01	60201
2004-10-01	61236
2005-01-01	63551
2005-04-01	63518
2005-07-01	63590
2005-10-01	64056
2006-01-01	64974
2006-04-01	64273
2006-07-01	63062
2006-10-01	64291
2007-01-01	63800
2007-04-01	64385
2007-07-01	65370
2007-10-01	67425
2008-01-01	67160
2008-04-01	66603
2008-07-01	64858
2008-10-01	62259
2009-01-01	60568
2009-04-01	64150
2009-07-01	68375
2009-10-01	76656
2010-01-01	80821
2010-04-01	87405
2010-07-01	92376
2010-10-01	92508
2011-01-01	97974
2011-04-01	103893
2011-07-01	108105
2011-10-01	112117
2012-01-01	120100
2012-04-01	121673
2012-07-01	132108
2012-10-01	138158
2013-01-01	141393
2013-04-01	146595
2013-07-01	157745
2013-10-01	172675
2014-01-01	179905
2014-04-01	190811
2014-07-01	191186
2014-10-01	194954
2015-01-01	199347
2015-04-01	208202
2015-07-01	206792
2015-10-01	208855
2016-01-01	231630
2016-04-01	233438
2016-07-01	235372
2016-10-01	237319
2017-01-01	244795
2017-04-01	244151
2017-07-01	258015
2017-10-01	258293
2018-01-01	270537
2018-04-01	271321