Quarter	Millions of US Dollars
1979-07-01	287
1979-10-01	433
1980-01-01	386
1980-04-01	426
1980-07-01	414
1980-10-01	383
1981-01-01	358
1981-04-01	313
1981-07-01	373
1981-10-01	434
1982-01-01	455
1982-04-01	486
1982-07-01	472
1982-10-01	508
1983-01-01	684
1983-04-01	716
1983-07-01	746
1983-10-01	1181
1984-01-01	1347
1984-04-01	1482
1984-07-01	2012
1984-10-01	2387
1985-01-01	2835
1985-04-01	3179
1985-07-01	3886
1985-10-01	4132
1986-01-01	5267
1986-04-01	6120
1986-07-01	6686
1986-10-01	7147
1987-01-01	7345
1987-04-01	7400
1987-07-01	7740
1987-10-01	7987
1988-01-01	7826
1988-04-01	7668
1988-07-01	7639
1988-10-01	8339
1989-01-01	7877
1989-04-01	7702
1989-07-01	8172
1989-10-01	8759
1990-01-01	8977
1990-04-01	10239
1990-07-01	10534
1990-10-01	10912
1991-01-01	11167
1991-04-01	10967
1991-07-01	11447
1991-10-01	12533
1992-01-01	12110
1992-04-01	12608
1992-07-01	12814
1992-10-01	11949
1993-01-01	12224
1993-04-01	12482
1993-07-01	15432
1993-10-01	15507
1994-01-01	16197
1994-04-01	16528
1994-07-01	17489
1994-10-01	18703
1995-01-01	20426
1995-04-01	21508
1995-07-01	21044
1995-10-01	20470
1996-01-01	18829
1996-04-01	17759
1996-07-01	16258
1996-10-01	15427
1997-01-01	14693
1997-04-01	14338
1997-07-01	14173
1997-10-01	14431
1998-01-01	13667
1998-04-01	12579
1998-07-01	12280
1998-10-01	12018
1999-01-01	11451
1999-04-01	10793
1999-07-01	10666
1999-10-01	8836
2000-01-01	8161
2000-04-01	7860
2000-07-01	7393
2000-10-01	7490
2001-01-01	11027
2001-04-01	15000
2001-07-01	15465
2001-10-01	14400
2002-01-01	17920
2002-04-01	18714
2002-07-01	18513
2002-10-01	19538
2003-01-01	20196
2003-04-01	21046
2003-07-01	21463
2003-10-01	21417
2004-01-01	21170
2004-04-01	21224
2004-07-01	21623
2004-10-01	22892
2005-01-01	21836
2005-04-01	20525
2005-07-01	19945
2005-10-01	19549
2006-01-01	20045
2006-04-01	21028
2006-07-01	14612
2006-10-01	15181
2007-01-01	15382
2007-04-01	22384
2007-07-01	23476
2007-10-01	24354
2008-01-01	25158
2008-04-01	32965
2008-07-01	31956
2008-10-01	31162
2009-01-01	30213
2009-04-01	39000
2009-07-01	43711
2009-10-01	43097
2010-01-01	48637
2010-04-01	45038
2010-07-01	49579
2010-10-01	48992
2011-01-01	51649
2011-04-01	53467
2011-07-01	43812
2011-10-01	42970
2012-01-01	39083
2012-04-01	37894
2012-07-01	30656
2012-10-01	31175
2013-01-01	24572
2013-04-01	26433
2013-07-01	31038
2013-10-01	31593
2014-01-01	24411
2014-04-01	24272
2014-07-01	22448
2014-10-01	22122
2015-01-01	20095
2015-04-01	20888
2015-07-01	21025
2015-10-01	20667
2016-01-01	16953
2016-04-01	17429
2016-07-01	20525
2016-10-01	20152
2017-01-01	20532
2017-04-01	20864
2017-07-01	20833
2017-10-01	22780
2018-01-01	21749
2018-04-01	20599