Quarter	Millions of US Dollars
1972-01-01	42
1972-04-01	42
1972-07-01	62
1972-10-01	62
1973-01-01	62
1973-04-01	62
1973-07-01	74
1973-10-01	110
1974-01-01	111
1974-04-01	110
1974-07-01	108
1974-10-01	158
1975-01-01	216
1975-04-01	241
1975-07-01	239
1975-10-01	264
1976-01-01	266
1976-04-01	266
1976-07-01	268
1976-10-01	325
1977-01-01	325
1977-04-01	446
1977-07-01	732
1977-10-01	1029
1978-01-01	1206
1978-04-01	1235
1978-07-01	1366
1978-10-01	1479
1979-01-01	1516
1979-04-01	1523
1979-07-01	1641
1979-10-01	1633
1980-01-01	1598
1980-04-01	1808
1980-07-01	1792
1980-10-01	1801
1981-01-01	1752
1981-04-01	2031
1981-07-01	2435
1981-10-01	2922
1982-01-01	3032
1982-04-01	3103
1982-07-01	3058
1982-10-01	3067
1983-01-01	3003
1983-04-01	2959
1983-07-01	2896
1983-10-01	2738
1984-01-01	2758
1984-04-01	2674
1984-07-01	2528
1984-10-01	2504
1985-01-01	2516
1985-04-01	2501
1985-07-01	2538
1985-10-01	2463
1986-01-01	2502
1986-04-01	2543
1986-07-01	2574
1986-10-01	2372
1987-01-01	2297
1987-04-01	2184
1987-07-01	2182
1987-10-01	2099
1988-01-01	2051
1988-04-01	1750
1988-07-01	1351
1988-10-01	1094
1989-01-01	1066
1989-04-01	927
1989-07-01	855
1989-10-01	908
1990-01-01	1949
1990-04-01	2510
1990-07-01	2833
1990-10-01	3242
1991-01-01	3373
1991-04-01	4284
1991-07-01	4457
1991-10-01	4596
1992-01-01	4652
1992-04-01	4861
1992-07-01	5227
1992-10-01	6657
1993-01-01	7175
1993-04-01	8909
1993-07-01	11072
1993-10-01	11928
1994-01-01	14777
1994-04-01	14790
1994-07-01	14998
1994-10-01	14609
1995-01-01	13124
1995-04-01	13149
1995-07-01	13353
1995-10-01	13358
1996-01-01	13024
1996-04-01	12936
1996-07-01	12557
1996-10-01	12797
1997-01-01	13246
1997-04-01	15455
1997-07-01	17677
1997-10-01	16966
1998-01-01	18008
1998-04-01	17931
1998-07-01	18910
1998-10-01	18962
1999-01-01	18386
1999-04-01	20171
1999-07-01	20327
1999-10-01	20287
2000-01-01	21430
2000-04-01	21517
2000-07-01	21458
2000-10-01	20493
2001-01-01	21289
2001-04-01	21193
2001-07-01	21704
2001-10-01	21339
2002-01-01	19982
2002-04-01	19080
2002-07-01	18033
2002-10-01	18183
2003-01-01	17294
2003-04-01	16364
2003-07-01	15491
2003-10-01	16390
2004-01-01	16664
2004-04-01	14789
2004-07-01	14740
2004-10-01	14538
2005-01-01	16334
2005-04-01	17059
2005-07-01	17175
2005-10-01	17974
2006-01-01	18419
2006-04-01	18256
2006-07-01	18243
2006-10-01	19665
2007-01-01	20763
2007-04-01	20711
2007-07-01	20031
2007-10-01	21683
2008-01-01	21389
2008-04-01	20594
2008-07-01	20428
2008-10-01	17696
2009-01-01	18336
2009-04-01	18910
2009-07-01	21180
2009-10-01	26561
2010-01-01	33071
2010-04-01	37951
2010-07-01	40756
2010-10-01	37843
2011-01-01	41438
2011-04-01	46085
2011-07-01	49745
2011-10-01	54060
2012-01-01	59220
2012-04-01	60403
2012-07-01	68707
2012-10-01	72730
2013-01-01	76826
2013-04-01	81464
2013-07-01	91613
2013-10-01	102976
2014-01-01	106334
2014-04-01	112180
2014-07-01	114018
2014-10-01	116407
2015-01-01	116587
2015-04-01	124605
2015-07-01	123657
2015-10-01	123862
2016-01-01	141662
2016-04-01	141029
2016-07-01	142121
2016-10-01	144080
2017-01-01	148221
2017-04-01	149438
2017-07-01	157818
2017-10-01	157777
2018-01-01	162394
2018-04-01	163386