Quarter	Millions of US Dollars
1968-07-01	40
1968-10-01	40
1969-01-01	40
1969-04-01	40
1969-07-01	40
1969-10-01	40
1970-01-01	40
1970-04-01	40
1970-07-01	40
1970-10-01	40
1971-01-01	128
1971-04-01	181
1971-07-01	209
1971-10-01	291
1972-01-01	498
1972-04-01	643
1972-07-01	857
1972-10-01	1243
1973-01-01	1455
1973-04-01	1945
1973-07-01	2081
1973-10-01	2525
1974-01-01	2755
1974-04-01	3236
1974-07-01	3276
1974-10-01	3527
1975-01-01	3895
1975-04-01	4449
1975-07-01	4494
1975-10-01	4723
1976-01-01	4944
1976-04-01	5392
1976-07-01	6120
1976-10-01	6721
1977-01-01	7357
1977-04-01	8277
1977-07-01	9609
1977-10-01	11466
1978-01-01	13484
1978-04-01	14871
1978-07-01	16461
1978-10-01	17868
1979-01-01	18556
1979-04-01	19294
1979-07-01	20521
1979-10-01	20598
1980-01-01	19489
1980-04-01	21247
1980-07-01	21725
1980-10-01	21501
1981-01-01	21032
1981-04-01	20714
1981-07-01	21481
1981-10-01	22979
1982-01-01	23152
1982-04-01	22988
1982-07-01	22601
1982-10-01	23905
1983-01-01	23331
1983-04-01	23233
1983-07-01	24434
1983-10-01	24225
1984-01-01	24831
1984-04-01	24248
1984-07-01	23887
1984-10-01	24839
1985-01-01	25939
1985-04-01	28271
1985-07-01	30647
1985-10-01	31466
1986-01-01	33831
1986-04-01	35504
1986-07-01	36688
1986-10-01	36207
1987-01-01	39719
1987-04-01	39077
1987-07-01	38798
1987-10-01	42385
1988-01-01	42284
1988-04-01	39645
1988-07-01	39413
1988-10-01	41970
1989-01-01	40895
1989-04-01	39436
1989-07-01	42177
1989-10-01	43290
1990-01-01	78688
1990-04-01	80008
1990-07-01	83476
1990-10-01	101830
1991-01-01	99911
1991-04-01	103299
1991-07-01	107282
1991-10-01	115285
1992-01-01	117406
1992-04-01	123348
1992-07-01	130847
1992-10-01	133876
1993-01-01	140338
1993-04-01	165244
1993-07-01	184229
1993-10-01	206074
1994-01-01	223008
1994-04-01	273912
1994-07-01	288511
1994-10-01	299425
1995-01-01	307591
1995-04-01	314832
1995-07-01	323257
1995-10-01	330606
1996-01-01	344008
1996-04-01	362779
1996-07-01	379660
1996-10-01	402434
1997-01-01	421761
1997-04-01	455855
1997-07-01	481047
1997-10-01	481685
1998-01-01	492661
1998-04-01	517739
1998-07-01	526821
1998-10-01	508410
1999-01-01	504906
1999-04-01	519565
1999-07-01	529436
1999-10-01	538818
2000-01-01	557495
2000-04-01	557047
2000-07-01	585863
2000-10-01	584810
2001-01-01	587220
2001-04-01	584003
2001-07-01	591107
2001-10-01	584007
2002-01-01	591061
2002-04-01	612841
2002-07-01	616011
2002-10-01	630912
2003-01-01	639314
2003-04-01	653726
2003-07-01	674643
2003-10-01	700556
2004-01-01	721078
2004-04-01	732112
2004-07-01	748021
2004-10-01	787164
2005-01-01	806963
2005-04-01	791478
2005-07-01	805808
2005-10-01	836046
2006-01-01	880365
2006-04-01	890586
2006-07-01	918460
2006-10-01	989916
2007-01-01	1042649
2007-04-01	1110627
2007-07-01	1128368
2007-10-01	1172812
2008-01-01	1192107
2008-04-01	1233577
2008-07-01	1214101
2008-10-01	1170614
2009-01-01	1152040
2009-04-01	1200285
2009-07-01	1262787
2009-10-01	1313170
2010-01-01	1329831
2010-04-01	1343600
2010-07-01	1440242
2010-10-01	1507505
2011-01-01	1592925
2011-04-01	1668320
2011-07-01	1662740
2011-10-01	1704643
2012-01-01	1809609
2012-04-01	1863460
2012-07-01	1971276
2012-10-01	2079135
2013-01-01	2144289
2013-04-01	2245584
2013-07-01	2328149
2013-10-01	2444408
2014-01-01	2505183
2014-04-01	2618626
2014-07-01	2646881
2014-10-01	2703990
2015-01-01	2711362
2015-04-01	2809050
2015-07-01	2803595
2015-10-01	2803306
2016-01-01	2847671
2016-04-01	2956608
2016-07-01	3036812
2016-10-01	3123613
2017-01-01	3244456
2017-04-01	3383429
2017-07-01	3506914
2017-10-01	3652668
2018-01-01	3776605
2018-04-01	3789993