Quarter	Millions of US Dollars
1975-04-01	53
1975-07-01	78
1975-10-01	78
1976-01-01	78
1976-04-01	78
1976-07-01	78
1976-10-01	78
1977-01-01	78
1977-04-01	78
1977-07-01	78
1977-10-01	78
1978-01-01	78
1978-04-01	78
1978-07-01	103
1978-10-01	103
1979-01-01	151
1979-04-01	184
1979-07-01	183
1979-10-01	180
1980-01-01	178
1980-04-01	184
1980-07-01	266
1980-10-01	292
1981-01-01	285
1981-04-01	304
1981-07-01	305
1981-10-01	311
1982-01-01	301
1982-04-01	297
1982-07-01	268
1982-10-01	278
1983-01-01	275
1983-04-01	273
1983-07-01	272
1983-10-01	271
1984-01-01	275
1984-04-01	268
1984-07-01	262
1984-10-01	259
1985-01-01	260
1985-04-01	261
1985-07-01	240
1985-10-01	247
1986-01-01	232
1986-04-01	241
1986-07-01	177
1986-10-01	116
1987-01-01	122
1987-04-01	121
1987-07-01	122
1987-10-01	136
1988-01-01	134
1988-04-01	128
1988-07-01	128
1988-10-01	133
1989-01-01	129
1989-04-01	123
1989-07-01	125
1989-10-01	123
1990-01-01	117
1990-04-01	66
1990-07-01	72
1990-10-01	74
1991-01-01	320
1991-04-01	320
1991-07-01	320
1991-10-01	320
1992-01-01	320
1992-04-01	320
1992-07-01	320
1992-10-01	320
1993-01-01	320
1993-04-01	653
1993-07-01	653
1993-10-01	753
1994-01-01	657
1994-04-01	657
1994-07-01	642
1994-10-01	742
1995-01-01	742
1995-04-01	742
1995-07-01	742
1995-10-01	742
1996-01-01	1172
1996-04-01	1892
1996-07-01	2332
1996-10-01	3132
1997-01-01	3882
1997-04-01	3882
1997-07-01	4182
1997-10-01	4832
1998-01-01	4832
1998-04-01	5332
1998-07-01	5332
1998-10-01	5745
1999-01-01	5945
1999-04-01	7145
1999-07-01	7441
1999-10-01	7428
2000-01-01	7418
2000-04-01	7418
2000-07-01	7703
2000-10-01	7713
2001-01-01	7704
2001-04-01	8302
2001-07-01	8671
2001-10-01	9315
2002-01-01	9313
2002-04-01	10237
2002-07-01	10602
2002-10-01	11449
2003-01-01	12398
2003-04-01	12673
2003-07-01	13544
2003-10-01	13330
2004-01-01	14153
2004-04-01	14150
2004-07-01	13905
2004-10-01	15142
2005-01-01	15040
2005-04-01	15163
2005-07-01	15106
2005-10-01	14906
2006-01-01	14249
2006-04-01	14349
2006-07-01	14149
2006-10-01	14349
2007-01-01	14483
2007-04-01	14483
2007-07-01	13796
2007-10-01	13611
2008-01-01	13002
2008-04-01	12931
2008-07-01	12920
2008-10-01	12913
2009-01-01	13503
2009-04-01	12452
2009-07-01	13309
2009-10-01	14762
2010-01-01	15258
2010-04-01	16136
2010-07-01	19603
2010-10-01	22217
2011-01-01	24345
2011-04-01	24638
2011-07-01	25480
2011-10-01	27215
2012-01-01	27636
2012-04-01	27417
2012-07-01	30519
2012-10-01	33198
2013-01-01	35311
2013-04-01	37296
2013-07-01	39067
2013-10-01	42653
2014-01-01	42733
2014-04-01	44560
2014-07-01	49421
2014-10-01	54165
2015-01-01	54837
2015-04-01	59514
2015-07-01	61085
2015-10-01	60436
2016-01-01	62858
2016-04-01	61975
2016-07-01	63033
2016-10-01	63440
2017-01-01	63919
2017-04-01	68392
2017-07-01	74449
2017-10-01	75327
2018-01-01	78098
2018-04-01	78249