Quarter	Billions of US Dollars
1990-01-01	2.727
1990-04-01	3.010
1990-07-01	3.185
1990-10-01	3.473
1991-01-01	3.099
1991-04-01	3.232
1991-07-01	3.513
1991-10-01	3.818
1992-01-01	3.163
1992-04-01	3.356
1992-07-01	3.008
1992-10-01	2.388
1993-01-01	2.480
1993-04-01	2.691
1993-07-01	2.822
1993-10-01	3.398
1994-01-01	3.358
1994-04-01	3.733
1994-07-01	4.214
1994-10-01	3.951
1995-01-01	4.239
1995-04-01	4.051
1995-07-01	4.322
1995-10-01	4.680
1996-01-01	3.937
1996-04-01	4.534
1996-07-01	5.445
1996-10-01	6.190
1997-01-01	4.458
1997-04-01	4.460
1997-07-01	4.923
1997-10-01	4.316
1998-01-01	3.183
1998-04-01	4.149
1998-07-01	4.089
1998-10-01	3.798
1999-01-01	3.513
1999-04-01	3.161
1999-07-01	2.998
1999-10-01	3.041
2000-01-01	2.958
2000-04-01	2.573
2000-07-01	2.258
2000-10-01	2.446
2001-01-01	2.245
2001-04-01	2.294
2001-07-01	2.266
2001-10-01	2.310
2002-01-01	2.471
2002-04-01	2.717
2002-07-01	2.521
2002-10-01	2.935
2003-01-01	2.963
2003-04-01	3.317
2003-07-01	4.748
2003-10-01	4.769
2004-01-01	4.272
2004-04-01	3.671
2004-07-01	3.758
2004-10-01	4.050
2005-01-01	4.001
2005-04-01	3.916
2005-07-01	3.811
2005-10-01	3.763
2006-01-01	3.268
2006-04-01	3.059
2006-07-01	2.177
2006-10-01	2.146
2007-01-01	1.682
2007-04-01	1.772
2007-07-01	1.847
2007-10-01	1.846
2008-01-01	1.377
2008-04-01	1.250
2008-07-01	1.309
2008-10-01	2.087
2009-01-01	3.097
2009-04-01	4.635
2009-07-01	6.712
2009-10-01	6.073
2010-01-01	5.980
2010-04-01	5.588
2010-07-01	5.381
2010-10-01	6.289
2011-01-01	5.877
2011-04-01	6.062
2011-07-01	6.223
2011-10-01	7.231
2012-01-01	7.417
2012-04-01	7.930
2012-07-01	6.596
2012-10-01	5.202
2013-01-01	4.251
2013-04-01	3.686
2013-07-01	3.941
2013-10-01	3.888
2014-01-01	3.396
2014-04-01	3.335
2014-07-01	3.014
2014-10-01	3.190
2015-01-01	4.105