Quarter	Billions of US Dollars
1997-10-01	178.723
1998-01-01	169.839
1998-04-01	179.860
1998-07-01	188.867
1998-10-01	196.850
1999-01-01	193.766
1999-04-01	190.191
1999-07-01	191.139
1999-10-01	190.060
2000-01-01	193.529
2000-04-01	202.795
2000-07-01	192.187
2000-10-01	211.112
2001-01-01	206.325
2001-04-01	200.533
2001-07-01	221.325
2001-10-01	227.910
2002-01-01	219.388
2002-04-01	259.139
2002-07-01	266.793
2002-10-01	298.612
2003-01-01	307.416
2003-04-01	334.567
2003-07-01	345.749
2003-10-01	387.410
2004-01-01	388.467
2004-04-01	401.991
2004-07-01	423.409
2004-10-01	478.533
2005-01-01	453.302
2005-04-01	449.347
2005-07-01	458.453
2005-10-01	459.925
2006-01-01	491.128
2006-04-01	523.550
2006-07-01	540.421
2006-10-01	578.507
2007-01-01	599.464
2007-04-01	612.207
2007-07-01	660.652
2007-10-01	710.861
2008-01-01	792.802
2008-04-01	799.149
2008-07-01	752.285
2008-10-01	746.132
2009-01-01	737.514
2009-04-01	807.060
2009-07-01	856.243
2009-10-01	825.842
2010-01-01	779.870
2010-04-01	676.625
2010-07-01	765.890
2010-10-01	743.800
2011-01-01	798.148
2011-04-01	781.732
2011-07-01	710.463
2011-10-01	618.021
2012-01-01	597.881
2012-04-01	595.862
2012-07-01	656.127
2012-10-01	714.156
2013-01-01	684.603
2013-04-01	711.886
2013-07-01	733.020
2013-10-01	747.879
2014-01-01	751.842
2014-04-01	750.640
2014-07-01	686.846
2014-10-01	653.615
2015-01-01	563.960
2015-04-01	582.130
2015-07-01	580.841
2015-10-01	574.805
2016-01-01	596.505
2016-04-01	587.724
2016-07-01	584.009
2016-10-01	556.323
2017-01-01	558.583
2017-04-01	593.121
2017-07-01	616.709
2017-10-01	640.578
2018-01-01	656.014