Quarter	Millions of US Dollars
1972-07-01	50
1972-10-01	50
1973-01-01	50
1973-04-01	80
1973-07-01	80
1973-10-01	80
1974-01-01	80
1974-04-01	131
1974-07-01	131
1974-10-01	132
1975-01-01	193
1975-04-01	275
1975-07-01	268
1975-10-01	288
1976-01-01	315
1976-04-01	354
1976-07-01	375
1976-10-01	378
1977-01-01	407
1977-04-01	428
1977-07-01	573
1977-10-01	695
1978-01-01	703
1978-04-01	749
1978-07-01	765
1978-10-01	772
1979-01-01	762
1979-04-01	858
1979-07-01	865
1979-10-01	861
1980-01-01	813
1980-04-01	895
1980-07-01	906
1980-10-01	896
1981-01-01	851
1981-04-01	735
1981-07-01	734
1981-10-01	744
1982-01-01	726
1982-04-01	720
1982-07-01	686
1982-10-01	682
1983-01-01	618
1983-04-01	554
1983-07-01	519
1983-10-01	501
1984-01-01	506
1984-04-01	446
1984-07-01	488
1984-10-01	482
1985-01-01	655
1985-04-01	635
1985-07-01	830
1985-10-01	806
1986-01-01	1009
1986-04-01	1436
1986-07-01	1549
1986-10-01	1653
1987-01-01	2308
1987-04-01	2263
1987-07-01	2246
1987-10-01	2923
1988-01-01	3715
1988-04-01	3927
1988-07-01	4394
1988-10-01	5367
1989-01-01	6003
1989-04-01	6100
1989-07-01	7430
1989-10-01	8194
1990-01-01	8725
1990-04-01	9108
1990-07-01	10103
1990-10-01	10921
1991-01-01	10189
1991-04-01	10169
1991-07-01	10964
1991-10-01	13235
1992-01-01	13302
1992-04-01	14262
1992-07-01	16361
1992-10-01	15987
1993-01-01	18797
1993-04-01	20358
1993-07-01	22742
1993-10-01	23747
1994-01-01	26328
1994-04-01	27582
1994-07-01	33595
1994-10-01	39910
1995-01-01	42189
1995-04-01	42913
1995-07-01	42139
1995-10-01	42336
1996-01-01	41988
1996-04-01	43163
1996-07-01	41035
1996-10-01	40665
1997-01-01	41845
1997-04-01	47360
1997-07-01	51066
1997-10-01	52365
1998-01-01	54222
1998-04-01	59688
1998-07-01	67215
1998-10-01	67691
1999-01-01	67032
1999-04-01	66889
1999-07-01	68555
1999-10-01	71574
2000-01-01	72759
2000-04-01	75481
2000-07-01	94259
2000-10-01	94500
2001-01-01	94378
2001-04-01	93932
2001-07-01	95986
2001-10-01	95739
2002-01-01	96543
2002-04-01	101441
2002-07-01	101714
2002-10-01	105040
2003-01-01	111663
2003-04-01	114290
2003-07-01	119900
2003-10-01	126656
2004-01-01	128989
2004-04-01	136804
2004-07-01	142239
2004-10-01	152777
2005-01-01	160827
2005-04-01	173081
2005-07-01	173422
2005-10-01	182251
2006-01-01	196068
2006-04-01	202565
2006-07-01	210639
2006-10-01	235064
2007-01-01	252105
2007-04-01	271438
2007-07-01	278551
2007-10-01	295824
2008-01-01	304157
2008-04-01	325880
2008-07-01	317982
2008-10-01	309030
2009-01-01	299792
2009-04-01	315618
2009-07-01	326591
2009-10-01	331518
2010-01-01	332181
2010-04-01	328564
2010-07-01	361394
2010-10-01	377216
2011-01-01	401136
2011-04-01	419408
2011-07-01	407048
2011-10-01	402018
2012-01-01	424419
2012-04-01	439818
2012-07-01	486348
2012-10-01	525063
2013-01-01	534208
2013-04-01	558610
2013-07-01	575489
2013-10-01	604813
2014-01-01	595421
2014-04-01	594166
2014-07-01	578204
2014-10-01	575121
2015-01-01	556098
2015-04-01	556529
2015-07-01	547018
2015-10-01	520100
2016-01-01	525451
2016-04-01	531801
2016-07-01	526125
2016-10-01	530090
2017-01-01	532567
2017-04-01	550060
2017-07-01	562442
2017-10-01	569817
2018-01-01	573160
2018-04-01	543120