Quarter	Millions of US Dollars
1970-10-01	15
1971-01-01	40
1971-04-01	40
1971-07-01	40
1971-10-01	145
1972-01-01	260
1972-04-01	403
1972-07-01	573
1972-10-01	731
1973-01-01	1207
1973-04-01	1646
1973-07-01	1871
1973-10-01	1976
1974-01-01	2137
1974-04-01	2205
1974-07-01	2241
1974-10-01	2461
1975-01-01	2480
1975-04-01	2698
1975-07-01	2689
1975-10-01	2782
1976-01-01	3155
1976-04-01	3481
1976-07-01	3621
1976-10-01	3855
1977-01-01	4005
1977-04-01	4308
1977-07-01	4513
1977-10-01	4927
1978-01-01	5423
1978-04-01	5820
1978-07-01	6200
1978-10-01	6236
1979-01-01	6322
1979-04-01	6485
1979-07-01	6643
1979-10-01	6784
1980-01-01	6502
1980-04-01	6772
1980-07-01	6682
1980-10-01	6369
1981-01-01	6222
1981-04-01	5887
1981-07-01	5827
1981-10-01	5766
1982-01-01	5615
1982-04-01	5445
1982-07-01	5352
1982-10-01	5525
1983-01-01	5382
1983-04-01	5236
1983-07-01	5167
1983-10-01	5085
1984-01-01	4932
1984-04-01	4813
1984-07-01	4824
1984-10-01	5034
1985-01-01	4952
1985-04-01	5074
1985-07-01	6137
1985-10-01	10208
1986-01-01	10563
1986-04-01	11891
1986-07-01	13327
1986-10-01	14292
1987-01-01	17071
1987-04-01	18574
1987-07-01	19157
1987-10-01	22159
1988-01-01	26337
1988-04-01	29103
1988-07-01	32661
1988-10-01	34116
1989-01-01	35973
1989-04-01	35423
1989-07-01	42119
1989-10-01	46547
1990-01-01	53462
1990-04-01	58408
1990-07-01	71558
1990-10-01	81412
1991-01-01	86739
1991-04-01	91387
1991-07-01	103493
1991-10-01	115035
1992-01-01	117787
1992-04-01	130634
1992-07-01	129553
1992-10-01	126575
1993-01-01	124389
1993-04-01	134555
1993-07-01	144277
1993-10-01	151962
1994-01-01	165327
1994-04-01	179211
1994-07-01	194594
1994-10-01	198318
1995-01-01	216769
1995-04-01	226070
1995-07-01	230015
1995-10-01	239040
1996-01-01	247441
1996-04-01	261949
1996-07-01	275005
1996-10-01	308821
1997-01-01	312358
1997-04-01	333925
1997-07-01	345958
1997-10-01	355036
1998-01-01	380318
1998-04-01	398292
1998-07-01	425958
1998-10-01	431394
1999-01-01	460686
1999-04-01	493129
1999-07-01	554945
1999-10-01	569481
2000-01-01	605698
2000-04-01	643475
2000-07-01	645710
2000-10-01	695383
2001-01-01	690353
2001-04-01	698081
2001-07-01	732660
2001-10-01	744015
2002-01-01	747963
2002-04-01	840956
2002-07-01	879853
2002-10-01	929231
2003-01-01	982266
2003-04-01	1069603
2003-07-01	1145250
2003-10-01	1292887
2004-01-01	1366792
2004-04-01	1429602
2004-07-01	1519568
2004-10-01	1707960
2005-01-01	1739085
2005-04-01	1741556
2005-07-01	1822421
2005-10-01	1889798
2006-01-01	2016032
2006-04-01	2161346
2006-07-01	2285409
2006-10-01	2490896
2007-01-01	2680655
2007-04-01	2876230
2007-07-01	3062125
2007-10-01	3154365
2008-01-01	3324280
2008-04-01	3546172
2008-07-01	3416169
2008-10-01	3427011
2009-01-01	3372600
2009-04-01	3681651
2009-07-01	3770318
2009-10-01	3710222
2010-01-01	3578445
2010-04-01	3404066
2010-07-01	3680751
2010-10-01	3527404
2011-01-01	3688422
2011-04-01	3745880
2011-07-01	3578697
2011-10-01	3470967
2012-01-01	3627919
2012-04-01	3471979
2012-07-01	3509457
2012-10-01	3491561
2013-01-01	3344735
2013-04-01	3299880
2013-07-01	3381464
2013-10-01	3440396
2014-01-01	3422964
2014-04-01	3456385
2014-07-01	3341758
2014-10-01	3230564
2015-01-01	3066912
2015-04-01	3191304
2015-07-01	3124690
2015-10-01	3034047
2016-01-01	3070549
2016-04-01	2971953
2016-07-01	2959836
2016-10-01	2864113
2017-01-01	2908163
2017-04-01	3029917
2017-07-01	3131007
2017-10-01	3170161
2018-01-01	3236339
2018-04-01	3149789