Quarter	Billions of US Dollars
1977-04-01	0.050
1977-07-01	0.050
1977-10-01	0.050
1978-01-01	0.050
1978-04-01	0.050
1978-07-01	0.050
1978-10-01	0.050
1979-01-01	0.050
1979-04-01	0.050
1979-07-01	0.050
1979-10-01	0.050
1980-01-01	0.050
1980-04-01	0.080
1980-07-01	0.080
1980-10-01	0.080
1981-01-01	0.080
1981-04-01	0.080
1981-07-01	0.080
1981-10-01	0.080
1982-01-01	0.080
1982-04-01	0.030
1982-07-01	0.049
1982-10-01	0.076
1983-01-01	0.096
1983-04-01	0.095
1983-07-01	0.096
1983-10-01	0.126
1984-01-01	0.250
1984-04-01	0.368
1984-07-01	0.403
1984-10-01	0.438
1985-01-01	0.477
1985-04-01	0.540
1985-07-01	0.731
1985-10-01	0.824
1986-01-01	0.965
1986-04-01	1.194
1986-07-01	1.396
1986-10-01	1.418
1987-01-01	1.626
1987-04-01	1.783
1987-07-01	2.131
1987-10-01	2.468
1988-01-01	2.869
1988-04-01	3.318
1988-07-01	3.245
1988-10-01	4.089
1989-01-01	3.922
1989-04-01	3.766
1989-07-01	3.925
1989-10-01	3.920
1990-01-01	3.850
1990-04-01	3.925
1990-07-01	4.165
1990-10-01	3.499
1991-01-01	2.500
1991-04-01	2.331
1991-07-01	2.444
1991-10-01	2.863
1992-01-01	2.658
1992-04-01	2.755
1992-07-01	2.677
1992-10-01	2.364
1993-01-01	2.975
1993-04-01	2.746
1993-07-01	3.731
1993-10-01	4.526
1994-01-01	5.434
1994-04-01	5.498
1994-07-01	7.155
1994-10-01	7.563
1995-01-01	9.111
1995-04-01	10.502
1995-07-01	9.893
1995-10-01	10.332
1996-01-01	10.961
1996-04-01	11.899
1996-07-01	11.683
1996-10-01	11.403
1997-01-01	10.965
1997-04-01	11.713
1997-07-01	11.889
1997-10-01	12.499
1998-01-01	12.866
1998-04-01	13.489
1998-07-01	14.320
1998-10-01	14.576
1999-01-01	12.038
1999-04-01	11.962
1999-07-01	12.055
1999-10-01	13.115
2000-01-01	12.439
2000-04-01	13.427
2000-07-01	13.196
2000-10-01	13.877
2001-01-01	15.413
2001-04-01	15.860
2001-07-01	16.995
2001-10-01	16.762
2002-01-01	19.431
2002-04-01	24.385
2002-07-01	24.443
2002-10-01	25.614
2003-01-01	29.078
2003-04-01	30.553
2003-07-01	30.961
2003-10-01	35.922
2004-01-01	33.288
2004-04-01	35.804
2004-07-01	35.862
2004-10-01	39.559
2005-01-01	38.469
2005-04-01	36.069
2005-07-01	35.721
2005-10-01	41.970
2006-01-01	46.670
2006-04-01	49.274
2006-07-01	52.047
2006-10-01	59.283
2007-01-01	60.376
2007-04-01	72.913
2007-07-01	74.673
2007-10-01	79.144
2008-01-01	90.822
2008-04-01	101.538
2008-07-01	94.504
2008-10-01	95.326
2009-01-01	103.339
2009-04-01	120.937
2009-07-01	133.629
2009-10-01	138.054
2010-01-01	132.181
2010-04-01	119.540
2010-07-01	133.419
2010-10-01	133.630
2011-01-01	142.899
2011-04-01	135.915
2011-07-01	125.090
2011-10-01	121.225
2012-01-01	119.546
2012-04-01	107.914
2012-07-01	104.207
2012-10-01	107.298
2013-01-01	102.339
2013-04-01	97.915
2013-07-01	100.136
2013-10-01	102.243
2014-01-01	100.154
2014-04-01	90.410
2014-07-01	86.904
2014-10-01	75.329
2015-01-01	65.787
2015-04-01	68.977