Quarter	Millions of US Dollars
1971-01-01	28
1971-04-01	29
1971-07-01	60
1971-10-01	61
1972-01-01	63
1972-04-01	95
1972-07-01	94
1972-10-01	94
1973-01-01	106
1973-04-01	123
1973-07-01	124
1973-10-01	111
1974-01-01	118
1974-04-01	117
1974-07-01	113
1974-10-01	124
1975-01-01	128
1975-04-01	149
1975-07-01	132
1975-10-01	134
1976-01-01	138
1976-04-01	175
1976-07-01	185
1976-10-01	190
1977-01-01	188
1977-04-01	235
1977-07-01	238
1977-10-01	261
1978-01-01	272
1978-04-01	265
1978-07-01	336
1978-10-01	357
1979-01-01	348
1979-04-01	352
1979-07-01	459
1979-10-01	462
1980-01-01	412
1980-04-01	483
1980-07-01	469
1980-10-01	434
1981-01-01	405
1981-04-01	355
1981-07-01	416
1981-10-01	433
1982-01-01	404
1982-04-01	440
1982-07-01	428
1982-10-01	508
1983-01-01	494
1983-04-01	485
1983-07-01	519
1983-10-01	502
1984-01-01	522
1984-04-01	485
1984-07-01	498
1984-10-01	550
1985-01-01	555
1985-04-01	561
1985-07-01	685
1985-10-01	815
1986-01-01	852
1986-04-01	901
1986-07-01	928
1986-10-01	1210
1987-01-01	1442
1987-04-01	1418
1987-07-01	1423
1987-10-01	1806
1988-01-01	1931
1988-04-01	1888
1988-07-01	2269
1988-10-01	2579
1989-01-01	2463
1989-04-01	2648
1989-07-01	2981
1989-10-01	3203
1990-01-01	3232
1990-04-01	3292
1990-07-01	3667
1990-10-01	3967
1991-01-01	3781
1991-04-01	3694
1991-07-01	4081
1991-10-01	4447
1992-01-01	4299
1992-04-01	4358
1992-07-01	4860
1992-10-01	4769
1993-01-01	4536
1993-04-01	4385
1993-07-01	4665
1993-10-01	4605
1994-01-01	4665
1994-04-01	4530
1994-07-01	4650
1994-10-01	5010
1995-01-01	5210
1995-04-01	5194
1995-07-01	5263
1995-10-01	5295
1996-01-01	5695
1996-04-01	5637
1996-07-01	5635
1996-10-01	5689
1997-01-01	5430
1997-04-01	5426
1997-07-01	5716
1997-10-01	5650
1998-01-01	5612
1998-04-01	5621
1998-07-01	5543
1998-10-01	5288
1999-01-01	5446
1999-04-01	5394
1999-07-01	5296
1999-10-01	5219
2000-01-01	5171
2000-04-01	5162
2000-07-01	4933
2000-10-01	4730
2001-01-01	4843
2001-04-01	4807
2001-07-01	4540
2001-10-01	4311
2002-01-01	4301
2002-04-01	4418
2002-07-01	4077
2002-10-01	3931
2003-01-01	3945
2003-04-01	3980
2003-07-01	3568
2003-10-01	3406
2004-01-01	3392
2004-04-01	3387
2004-07-01	3147
2004-10-01	2773
2005-01-01	2725
2005-04-01	3017
2005-07-01	2761
2005-10-01	2684
2006-01-01	2266
2006-04-01	2776
2006-07-01	2766
2006-10-01	2390
2007-01-01	2410
2007-04-01	2435
2007-07-01	2065
2007-10-01	2129
2008-01-01	2765
2008-04-01	2755
2008-07-01	2540
2008-10-01	2488
2009-01-01	2095
2009-04-01	2721
2009-07-01	2822
2009-10-01	2535
2010-01-01	2412
2010-04-01	2287
2010-07-01	2498
2010-10-01	2477
2011-01-01	2403
2011-04-01	2451
2011-07-01	2360
2011-10-01	2284
2012-01-01	2950
2012-04-01	3753
2012-07-01	3811
2012-10-01	3781
2013-01-01	3681
2013-04-01	4691
2013-07-01	4752
2013-10-01	4752
2014-01-01	4760
2014-04-01	5752
2014-07-01	5579
2014-10-01	5485
2015-01-01	5309
2015-04-01	6355
2015-07-01	6364
2015-10-01	6404
2016-01-01	6501
2016-04-01	7504
2016-07-01	7520
2016-10-01	7371
2017-01-01	6765
2017-04-01	6476
2017-07-01	6525
2017-10-01	6548
2018-01-01	6614
2018-04-01	6009