Quarter	Billions of US Dollars
1968-07-01	0.0400
1972-04-01	0.0252
1972-10-01	0.0500
1973-01-01	0.0300
1973-04-01	0.0366
1973-10-01	0.0204
1974-01-01	0.0662
1974-04-01	0.0172
1974-10-01	0.0189
1975-01-01	0.0448
1975-10-01	0.0175
1976-04-01	0.0134
1976-07-01	0.3981
1976-10-01	0.0515
1977-01-01	0.0876
1977-04-01	0.0366
1977-07-01	0.0869
1977-10-01	0.0465
1978-01-01	0.1801
1978-04-01	0.1464
1978-07-01	0.1298
1978-10-01	0.1284
1979-01-01	0.2734
1979-04-01	0.1263
1979-07-01	0.2412
1980-04-01	0.0760
1980-07-01	0.1416
1980-10-01	0.0473
1981-04-01	0.0664
1981-07-01	0.1161
1981-10-01	0.2040
1982-01-01	0.4700
1982-04-01	0.2905
1982-07-01	0.0373
1982-10-01	0.4870
1983-01-01	0.1157
1983-04-01	0.3327
1983-07-01	1.2733
1983-10-01	0.1790
1984-01-01	0.5275
1984-04-01	0.2021
1984-07-01	0.4355
1984-10-01	1.1184
1985-01-01	1.4657
1985-04-01	0.9235
1985-07-01	1.4421
1985-10-01	1.6058
1986-01-01	1.4148
1986-04-01	0.7119
1986-07-01	0.2373
1986-10-01	0.2812
1987-01-01	0.6312
1987-04-01	0.4689
1987-07-01	0.6536
1987-10-01	0.4471
1988-01-01	0.7057
1988-04-01	0.5261
1988-07-01	0.6943
1988-10-01	0.5094
1989-01-01	0.5332
1989-04-01	0.1000
1989-07-01	0.7186
1989-10-01	0.5204
1990-01-01	0.3450
1990-04-01	1.3689
1990-07-01	0.7095
1990-10-01	1.2204
1991-01-01	1.0724
1991-04-01	1.6973
1991-07-01	0.6960
1991-10-01	0.7204
1992-01-01	1.3086
1992-04-01	0.7516
1992-07-01	1.7098
1992-10-01	5.0095
1993-01-01	1.6933
1993-04-01	2.7646
1993-07-01	2.6699
1993-10-01	7.1097
1994-01-01	5.5913
1994-04-01	5.0793
1994-07-01	6.1388
1994-10-01	2.1128
1995-01-01	2.5675
1995-04-01	2.4382
1995-07-01	6.6840
1995-10-01	3.9807
1996-01-01	7.7120
1996-04-01	10.1189
1996-07-01	11.4892
1996-10-01	13.4300
1997-01-01	10.2848
1997-04-01	15.5477
1997-07-01	13.4865
1997-10-01	5.5305
1998-01-01	3.0875
1998-04-01	7.9666
1998-07-01	0.5137
1998-10-01	3.1834
1999-01-01	4.4694
1999-04-01	5.6280
1999-07-01	4.3493
1999-10-01	5.4068
2000-01-01	7.5904
2000-04-01	3.0546
2000-07-01	3.7007
2000-10-01	3.7629
2001-01-01	2.6374
2001-04-01	5.9558
2001-07-01	2.8471
2001-10-01	8.0715
2002-01-01	8.4553
2002-04-01	13.4458
2002-07-01	8.5806
2002-10-01	16.9917
2003-01-01	13.0277
2003-04-01	14.5698
2003-07-01	11.0484
2003-10-01	12.6058
2004-01-01	15.4334
2004-04-01	13.7854
2004-07-01	13.3040
2004-10-01	16.5745
2005-01-01	14.1042
2005-04-01	11.6874
2005-07-01	14.3518
2005-10-01	17.5251
2006-01-01	18.0527
2006-04-01	13.3259
2006-07-01	16.7899
2006-10-01	19.7452
2007-01-01	23.4214
2007-04-01	32.5234
2007-07-01	9.9659
2007-10-01	13.1095
2008-01-01	9.6543
2008-04-01	17.7527
2008-07-01	11.0604
2008-10-01	4.4737
2009-01-01	13.8974
2009-04-01	18.6245
2009-07-01	23.5518
2009-10-01	18.0385
2010-01-01	20.5323
2010-04-01	18.9483
2010-07-01	30.6415
2010-10-01	34.0992
2011-01-01	33.4557
2011-04-01	51.0103
2011-07-01	23.4103
2011-10-01	20.7464
2012-01-01	44.6910
2012-04-01	50.4439
2012-07-01	34.0549
2012-10-01	40.4742
2013-01-01	45.5618
2013-04-01	60.1939
2013-07-01	41.2383
2013-10-01	50.0068
2014-01-01	50.7993
2014-04-01	88.1038
2014-07-01	61.2356
2014-10-01	86.0622
2015-01-01	60.5961
2015-04-01	79.7104