Quarter	Millions of US Dollars
1966-01-01	20
1966-04-01	20
1966-07-01	20
1966-10-01	20
1967-01-01	20
1967-04-01	20
1967-07-01	20
1967-10-01	35
1968-01-01	35
1968-04-01	35
1968-07-01	35
1968-10-01	35
1969-01-01	35
1969-04-01	35
1969-07-01	35
1969-10-01	35
1970-01-01	35
1970-04-01	35
1970-07-01	35
1970-10-01	35
1971-01-01	80
1971-04-01	101
1971-07-01	118
1971-10-01	118
1972-01-01	208
1972-04-01	239
1972-07-01	262
1972-10-01	314
1973-01-01	361
1973-04-01	428
1973-07-01	426
1973-10-01	434
1974-01-01	472
1974-04-01	521
1974-07-01	528
1974-10-01	611
1975-01-01	843
1975-04-01	1022
1975-07-01	1026
1975-10-01	1318
1976-01-01	1531
1976-04-01	1663
1976-07-01	1880
1976-10-01	2264
1977-01-01	2382
1977-04-01	2546
1977-07-01	2744
1977-10-01	3030
1978-01-01	3258
1978-04-01	3290
1978-07-01	3592
1978-10-01	3578
1979-01-01	3512
1979-04-01	3593
1979-07-01	3719
1979-10-01	3650
1980-01-01	3356
1980-04-01	3493
1980-07-01	3402
1980-10-01	3157
1981-01-01	2987
1981-04-01	2812
1981-07-01	2885
1981-10-01	3009
1982-01-01	2981
1982-04-01	2882
1982-07-01	2881
1982-10-01	2972
1983-01-01	3059
1983-04-01	2994
1983-07-01	2820
1983-10-01	2710
1984-01-01	2794
1984-04-01	2727
1984-07-01	2615
1984-10-01	2483
1985-01-01	2476
1985-04-01	2497
1985-07-01	2785
1985-10-01	2730
1986-01-01	3179
1986-04-01	3580
1986-07-01	4144
1986-10-01	4269
1987-01-01	4584
1987-04-01	4909
1987-07-01	4863
1987-10-01	5144
1988-01-01	4790
1988-04-01	4806
1988-07-01	4615
1988-10-01	4984
1989-01-01	5056
1989-04-01	5000
1989-07-01	5470
1989-10-01	6279
1990-01-01	6370
1990-04-01	6608
1990-07-01	6776
1990-10-01	6784
1991-01-01	6283
1991-04-01	6211
1991-07-01	6584
1991-10-01	6964
1992-01-01	6317
1992-04-01	7146
1992-07-01	7374
1992-10-01	6476
1993-01-01	6244
1993-04-01	5906
1993-07-01	5901
1993-10-01	5673
1994-01-01	5882
1994-04-01	5597
1994-07-01	5440
1994-10-01	5017
1995-01-01	5378
1995-04-01	5401
1995-07-01	5347
1995-10-01	5220
1996-01-01	4334
1996-04-01	3646
1996-07-01	3470
1996-10-01	3464
1997-01-01	3770
1997-04-01	3595
1997-07-01	3278
1997-10-01	3492
1998-01-01	3667
1998-04-01	4636
1998-07-01	4542
1998-10-01	4790
1999-01-01	5156
1999-04-01	7050
1999-07-01	7676
1999-10-01	8376
2000-01-01	8477
2000-04-01	7431
2000-07-01	8744
2000-10-01	9364
2001-01-01	10769
2001-04-01	13896
2001-07-01	13631
2001-10-01	14250
2002-01-01	14205
2002-04-01	15709
2002-07-01	15328
2002-10-01	16138
2003-01-01	16382
2003-04-01	16738
2003-07-01	16286
2003-10-01	15535
2004-01-01	15891
2004-04-01	16040
2004-07-01	15375
2004-10-01	16442
2005-01-01	15835
2005-04-01	17770
2005-07-01	17479
2005-10-01	17615
2006-01-01	17679
2006-04-01	16138
2006-07-01	16561
2006-10-01	17465
2007-01-01	18557
2007-04-01	23945
2007-07-01	24826
2007-10-01	26804
2008-01-01	27282
2008-04-01	26486
2008-07-01	24038
2008-10-01	22855
2009-01-01	27903
2009-04-01	33684
2009-07-01	34674
2009-10-01	34907
2010-01-01	33299
2010-04-01	28871
2010-07-01	31590
2010-10-01	32142
2011-01-01	34661
2011-04-01	39665
2011-07-01	40043
2011-10-01	41457
2012-01-01	48306
2012-04-01	46903
2012-07-01	52076
2012-10-01	55025
2013-01-01	54905
2013-04-01	54568
2013-07-01	56628
2013-10-01	61032
2014-01-01	61776
2014-04-01	64146
2014-07-01	59405
2014-10-01	60030
2015-01-01	57654
2015-04-01	61318
2015-07-01	63275
2015-10-01	63918
2016-01-01	64837
2016-04-01	64780
2016-07-01	65924
2016-10-01	66816
2017-01-01	73434
2017-04-01	79392
2017-07-01	83077
2017-10-01	86499
2018-01-01	90070
2018-04-01	86509