Quarter	Millions of US Dollars
1971-01-01	88
1971-04-01	141
1971-07-01	169
1971-10-01	221
1972-01-01	345
1972-04-01	424
1972-07-01	539
1972-10-01	729
1973-01-01	801
1973-04-01	1174
1973-07-01	1232
1973-10-01	1570
1974-01-01	1715
1974-04-01	2133
1974-07-01	2182
1974-10-01	2319
1975-01-01	2442
1975-04-01	2768
1975-07-01	2807
1975-10-01	2932
1976-01-01	3054
1976-04-01	3257
1976-07-01	3409
1976-10-01	3672
1977-01-01	3874
1977-04-01	4093
1977-07-01	4288
1977-10-01	4663
1978-01-01	5130
1978-04-01	5580
1978-07-01	6134
1978-10-01	6700
1979-01-01	6850
1979-04-01	7136
1979-07-01	7404
1979-10-01	7359
1980-01-01	7044
1980-04-01	7281
1980-07-01	7373
1980-10-01	7145
1981-01-01	7010
1981-04-01	6712
1981-07-01	6841
1981-10-01	6907
1982-01-01	6733
1982-04-01	6743
1982-07-01	6628
1982-10-01	6863
1983-01-01	6931
1983-04-01	6966
1983-07-01	6962
1983-10-01	6912
1984-01-01	6967
1984-04-01	7045
1984-07-01	7016
1984-10-01	7258
1985-01-01	7399
1985-04-01	8182
1985-07-01	8550
1985-10-01	7632
1986-01-01	7588
1986-04-01	7648
1986-07-01	7873
1986-10-01	7717
1987-01-01	7927
1987-04-01	7649
1987-07-01	7275
1987-10-01	7291
1988-01-01	7022
1988-04-01	6469
1988-07-01	6185
1988-10-01	6481
1989-01-01	6051
1989-04-01	5487
1989-07-01	5751
1989-10-01	5914
1990-01-01	5717
1990-04-01	4942
1990-07-01	4642
1990-10-01	4391
1991-01-01	3821
1991-04-01	4634
1991-07-01	4659
1991-10-01	4990
1992-01-01	7309
1992-04-01	8046
1992-07-01	8355
1992-10-01	7743
1993-01-01	8064
1993-04-01	6330
1993-07-01	7779
1993-10-01	8373
1994-01-01	9192
1994-04-01	8867
1994-07-01	9231
1994-10-01	9919
1995-01-01	10605
1995-04-01	10792
1995-07-01	11100
1995-10-01	11660
1996-01-01	12138
1996-04-01	12199
1996-07-01	12805
1996-10-01	15338
1997-01-01	15034
1997-04-01	16516
1997-07-01	17522
1997-10-01	18107
1998-01-01	19859
1998-04-01	20387
1998-07-01	21062
1998-10-01	21526
1999-01-01	22401
1999-04-01	25227
1999-07-01	26238
1999-10-01	26576
2000-01-01	28306
2000-04-01	29950
2000-07-01	30678
2000-10-01	30810
2001-01-01	30607
2001-04-01	32776
2001-07-01	35578
2001-10-01	35575
2002-01-01	36251
2002-04-01	40058
2002-07-01	39991
2002-10-01	41687
2003-01-01	43270
2003-04-01	45935
2003-07-01	51034
2003-10-01	52303
2004-01-01	58193
2004-04-01	59881
2004-07-01	60965
2004-10-01	64882
2005-01-01	65610
2005-04-01	66918
2005-07-01	73605
2005-10-01	78873
2006-01-01	90126
2006-04-01	96904
2006-07-01	101219
2006-10-01	120551
2007-01-01	130112
2007-04-01	140217
2007-07-01	151053
2007-10-01	159592
2008-01-01	160866
2008-04-01	169750
2008-07-01	169557
2008-10-01	162269
2009-01-01	157946
2009-04-01	176176
2009-07-01	189168
2009-10-01	198746
2010-01-01	199832
2010-04-01	200947
2010-07-01	214143
2010-10-01	226852
2011-01-01	240541
2011-04-01	241116
2011-07-01	235711
2011-10-01	252063
2012-01-01	262240
2012-04-01	259039
2012-07-01	269229
2012-10-01	290815
2013-01-01	300225
2013-04-01	305953
2013-07-01	315469
2013-10-01	329363
2014-01-01	332147
2014-04-01	346346
2014-07-01	346699
2014-10-01	347829
2015-01-01	356564
2015-04-01	372927
2015-07-01	372888
2015-10-01	376380
2016-01-01	385919
2016-04-01	418225
2016-07-01	445165
2016-10-01	488937
2017-01-01	506420
2017-04-01	535451
2017-07-01	535390
2017-10-01	565119
2018-01-01	594474
2018-04-01	628891