Quarter	Millions of US Dollars
1971-01-01	30
1971-04-01	30
1971-07-01	54
1971-10-01	85
1972-01-01	161
1972-04-01	231
1972-07-01	271
1972-10-01	413
1973-01-01	428
1973-04-01	587
1973-07-01	642
1973-10-01	967
1974-01-01	1072
1974-04-01	1433
1974-07-01	1458
1974-10-01	1550
1975-01-01	1620
1975-04-01	1689
1975-07-01	1711
1975-10-01	1739
1976-01-01	1804
1976-04-01	1858
1976-07-01	1914
1976-10-01	1998
1977-01-01	2154
1977-04-01	2211
1977-07-01	2259
1977-10-01	2353
1978-01-01	2491
1978-04-01	2607
1978-07-01	2705
1978-10-01	2824
1979-01-01	2811
1979-04-01	2876
1979-07-01	2936
1979-10-01	2910
1980-01-01	2846
1980-04-01	2956
1980-07-01	2929
1980-10-01	2859
1981-01-01	2785
1981-04-01	2729
1981-07-01	2741
1981-10-01	2760
1982-01-01	2666
1982-04-01	2648
1982-07-01	2687
1982-10-01	2714
1983-01-01	2702
1983-04-01	2712
1983-07-01	2739
1983-10-01	2730
1984-01-01	2861
1984-04-01	2904
1984-07-01	2934
1984-10-01	2984
1985-01-01	3037
1985-04-01	2985
1985-07-01	3119
1985-10-01	2718
1986-01-01	2674
1986-04-01	2668
1986-07-01	2707
1986-10-01	2634
1987-01-01	2596
1987-04-01	2458
1987-07-01	2281
1987-10-01	2339
1988-01-01	2221
1988-04-01	2030
1988-07-01	1957
1988-10-01	2102
1989-01-01	1881
1989-04-01	1721
1989-07-01	1693
1989-10-01	1697
1990-01-01	1641
1990-04-01	1469
1990-07-01	1442
1990-10-01	1363
1991-01-01	1157
1991-04-01	1988
1991-07-01	2036
1991-10-01	2221
1992-01-01	4476
1992-04-01	4552
1992-07-01	4622
1992-10-01	4320
1993-01-01	4316
1993-04-01	4252
1993-07-01	4362
1993-10-01	5029
1994-01-01	5605
1994-04-01	5305
1994-07-01	5381
1994-10-01	5952
1995-01-01	6027
1995-04-01	6306
1995-07-01	6243
1995-10-01	6429
1996-01-01	6557
1996-04-01	6536
1996-07-01	6824
1996-10-01	7335
1997-01-01	7178
1997-04-01	7992
1997-07-01	8114
1997-10-01	7981
1998-01-01	9288
1998-04-01	9233
1998-07-01	9299
1998-10-01	9489
1999-01-01	9344
1999-04-01	12090
1999-07-01	12229
1999-10-01	11773
2000-01-01	12942
2000-04-01	13992
2000-07-01	13815
2000-10-01	13878
2001-01-01	13769
2001-04-01	14302
2001-07-01	16396
2001-10-01	16160
2002-01-01	16490
2002-04-01	18002
2002-07-01	17715
2002-10-01	17310
2003-01-01	17404
2003-04-01	19708
2003-07-01	20382
2003-10-01	20084
2004-01-01	20476
2004-04-01	21828
2004-07-01	21898
2004-10-01	22926
2005-01-01	22633
2005-04-01	22266
2005-07-01	23462
2005-10-01	24004
2006-01-01	26656
2006-04-01	26536
2006-07-01	25979
2006-10-01	25967
2007-01-01	25755
2007-04-01	27384
2007-07-01	29132
2007-10-01	30678
2008-01-01	31210
2008-04-01	32177
2008-07-01	30961
2008-10-01	30821
2009-01-01	31504
2009-04-01	39812
2009-07-01	40505
2009-10-01	47581
2010-01-01	50744
2010-04-01	53880
2010-07-01	54552
2010-10-01	57922
2011-01-01	59737
2011-04-01	60893
2011-07-01	59756
2011-10-01	64886
2012-01-01	66960
2012-04-01	65330
2012-07-01	68885
2012-10-01	70480
2013-01-01	72783
2013-04-01	71865
2013-07-01	77055
2013-10-01	81071
2014-01-01	82629
2014-04-01	81887
2014-07-01	86457
2014-10-01	84892
2015-01-01	83172
2015-04-01	86580
2015-07-01	87824
2015-10-01	92960
2016-01-01	95293
2016-04-01	118540
2016-07-01	118919
2016-10-01	159234
2017-01-01	175438
2017-04-01	195059
2017-07-01	200464
2017-10-01	226151
2018-01-01	244937
2018-04-01	280633