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	548
1975-04-01	625
1975-07-01	631
1975-10-01	694
1976-01-01	762
1976-04-01	905
1976-07-01	1012
1976-10-01	1099
1977-01-01	1217
1977-04-01	1541
1977-07-01	2029
1977-10-01	2646
1978-01-01	3206
1978-04-01	3334
1978-07-01	3678
1978-10-01	3801
1979-01-01	3708
1979-04-01	3722
1979-07-01	4015
1979-10-01	3988
1980-01-01	3698
1980-04-01	4111
1980-07-01	4071
1980-10-01	4013
1981-01-01	3947
1981-04-01	4281
1981-07-01	4645
1981-10-01	5453
1982-01-01	5813
1982-04-01	5747
1982-07-01	5772
1982-10-01	5825
1983-01-01	5556
1983-04-01	5418
1983-07-01	5318
1983-10-01	5115
1984-01-01	5120
1984-04-01	4938
1984-07-01	4686
1984-10-01	4609
1985-01-01	4565
1985-04-01	4542
1985-07-01	4571
1985-10-01	4353
1986-01-01	4438
1986-04-01	4374
1986-07-01	4334
1986-10-01	4130
1987-01-01	4392
1987-04-01	4098
1987-07-01	4198
1987-10-01	4095
1988-01-01	3808
1988-04-01	3282
1988-07-01	2692
1988-10-01	2328
1989-01-01	2089
1989-04-01	2039
1989-07-01	2062
1989-10-01	1981
1990-01-01	37397
1990-04-01	38202
1990-07-01	39371
1990-10-01	40265
1991-01-01	38983
1991-04-01	39901
1991-07-01	40958
1991-10-01	42625
1992-01-01	41899
1992-04-01	42482
1992-07-01	44064
1992-10-01	45848
1993-01-01	46877
1993-04-01	50025
1993-07-01	54408
1993-10-01	55380
1994-01-01	60450
1994-04-01	62293
1994-07-01	63667
1994-10-01	62073
1995-01-01	58396
1995-04-01	59147
1995-07-01	61720
1995-10-01	62027
1996-01-01	64929
1996-04-01	65182
1996-07-01	71975
1996-10-01	71631
1997-01-01	72766
1997-04-01	76414
1997-07-01	73091
1997-10-01	72198
1998-01-01	73594
1998-04-01	72583
1998-07-01	73789
1998-10-01	75156
1999-01-01	75765
1999-04-01	79843
1999-07-01	82308
1999-10-01	83367
2000-01-01	86711
2000-04-01	85865
2000-07-01	86666
2000-10-01	85531
2001-01-01	91057
2001-04-01	87030
2001-07-01	87343
2001-10-01	81056
2002-01-01	82359
2002-04-01	78792
2002-07-01	77992
2002-10-01	80618
2003-01-01	73811
2003-04-01	73000
2003-07-01	70295
2003-10-01	71907
2004-01-01	74085
2004-04-01	74892
2004-07-01	77858
2004-10-01	79647
2005-01-01	82353
2005-04-01	80940
2005-07-01	81853
2005-10-01	82653
2006-01-01	83736
2006-04-01	82649
2006-07-01	81412
2006-10-01	84727
2007-01-01	86210
2007-04-01	86515
2007-07-01	85462
2007-10-01	88876
2008-01-01	88037
2008-04-01	88946
2008-07-01	86404
2008-10-01	82219
2009-01-01	79587
2009-04-01	80638
2009-07-01	84825
2009-10-01	92989
2010-01-01	95842
2010-04-01	98980
2010-07-01	105134
2010-10-01	102179
2011-01-01	105706
2011-04-01	111528
2011-07-01	115875
2011-10-01	119231
2012-01-01	127993
2012-04-01	130010
2012-07-01	138674
2012-10-01	144881
2013-01-01	147820
2013-04-01	150628
2013-07-01	162323
2013-10-01	173090
2014-01-01	179824
2014-04-01	189297
2014-07-01	189330
2014-10-01	192674
2015-01-01	196314
2015-04-01	208509
2015-07-01	207599
2015-10-01	208735
2016-01-01	232905
2016-04-01	234508
2016-07-01	236679
2016-10-01	238577
2017-01-01	246687
2017-04-01	246020
2017-07-01	260249
2017-10-01	260100
2018-01-01	269548
2018-04-01	269743