Quarter	Millions of US Dollars
1971-10-01	15
1972-01-01	35
1972-04-01	87
1972-07-01	86
1972-10-01	106
1973-01-01	110
1973-04-01	116
1973-07-01	193
1973-10-01	217
1974-01-01	271
1974-04-01	271
1974-07-01	279
1974-10-01	287
1975-01-01	313
1975-04-01	325
1975-07-01	316
1975-10-01	338
1976-01-01	341
1976-04-01	366
1976-07-01	430
1976-10-01	518
1977-01-01	580
1977-04-01	693
1977-07-01	775
1977-10-01	866
1978-01-01	1003
1978-04-01	1013
1978-07-01	1069
1978-10-01	1111
1979-01-01	1187
1979-04-01	1178
1979-07-01	1187
1979-10-01	1174
1980-01-01	1138
1980-04-01	1172
1980-07-01	1197
1980-10-01	1188
1981-01-01	1238
1981-04-01	1197
1981-07-01	1153
1981-10-01	1212
1982-01-01	1159
1982-04-01	1144
1982-07-01	1181
1982-10-01	1228
1983-01-01	1143
1983-04-01	1110
1983-07-01	1140
1983-10-01	1254
1984-01-01	1343
1984-04-01	1326
1984-07-01	1286
1984-10-01	1352
1985-01-01	1420
1985-04-01	1530
1985-07-01	1534
1985-10-01	1579
1986-01-01	1516
1986-04-01	1521
1986-07-01	1681
1986-10-01	1850
1987-01-01	3603
1987-04-01	3527
1987-07-01	3775
1987-10-01	4029
1988-01-01	4980
1988-04-01	4820
1988-07-01	4689
1988-10-01	4645
1989-01-01	4482
1989-04-01	5104
1989-07-01	5204
1989-10-01	5287
1990-01-01	5801
1990-04-01	6769
1990-07-01	7106
1990-10-01	6579
1991-01-01	6479
1991-04-01	6958
1991-07-01	6958
1991-10-01	7427
1992-01-01	8618
1992-04-01	9371
1992-07-01	8947
1992-10-01	7478
1993-01-01	7615
1993-04-01	8783
1993-07-01	6693
1993-10-01	9635
1994-01-01	12341
1994-04-01	13515
1994-07-01	15173
1994-10-01	17545
1995-01-01	16479
1995-04-01	16173
1995-07-01	17044
1995-10-01	18313
1996-01-01	20845
1996-04-01	21079
1996-07-01	26044
1996-10-01	29269
1997-01-01	32716
1997-04-01	37361
1997-07-01	42820
1997-10-01	42668
1998-01-01	43443
1998-04-01	48456
1998-07-01	50918
1998-10-01	51079
1999-01-01	58368
1999-04-01	58780
1999-07-01	61702
1999-10-01	64572
2000-01-01	65735
2000-04-01	71266
2000-07-01	76636
2000-10-01	80034
2001-01-01	87922
2001-04-01	95607
2001-07-01	101670
2001-10-01	106343
2002-01-01	109491
2002-04-01	113530
2002-07-01	112876
2002-10-01	119729
2003-01-01	122447
2003-04-01	126226
2003-07-01	129933
2003-10-01	141611
2004-01-01	140817
2004-04-01	145094
2004-07-01	149496
2004-10-01	163174
2005-01-01	164067
2005-04-01	170522
2005-07-01	177379
2005-10-01	182455
2006-01-01	187323
2006-04-01	200473
2006-07-01	206769
2006-10-01	215081
2007-01-01	222798
2007-04-01	237339
2007-07-01	242948
2007-10-01	246815
2008-01-01	255684
2008-04-01	259105
2008-07-01	255736
2008-10-01	248078
2009-01-01	234396
2009-04-01	250467
2009-07-01	259844
2009-10-01	264950
2010-01-01	267492
2010-04-01	260642
2010-07-01	273543
2010-10-01	274874
2011-01-01	269821
2011-04-01	276744
2011-07-01	274893
2011-10-01	278909
2012-01-01	298298
2012-04-01	304156
2012-07-01	320537
2012-10-01	341988
2013-01-01	348270
2013-04-01	355744
2013-07-01	363764
2013-10-01	365843
2014-01-01	370966
2014-04-01	373013
2014-07-01	377615
2014-10-01	372599
2015-01-01	374016
2015-04-01	380639
2015-07-01	369382
2015-10-01	369810
2016-01-01	377613
2016-04-01	379640
2016-07-01	375080
2016-10-01	375298
2017-01-01	382873
2017-04-01	391619
2017-07-01	419203
2017-10-01	420891
2018-01-01	433597
2018-04-01	459702