Quarter	Billions of US Dollars
1987-01-01	4.129
1987-04-01	4.078
1987-07-01	4.171
1987-10-01	5.104
1988-01-01	5.647
1988-04-01	5.615
1988-07-01	5.805
1988-10-01	6.446
1989-01-01	6.460
1989-04-01	6.205
1989-07-01	6.749
1989-10-01	6.973
1990-01-01	6.811
1990-04-01	7.570
1990-07-01	8.340
1990-10-01	9.168
1991-01-01	9.627
1991-04-01	9.649
1991-07-01	10.114
1991-10-01	12.150
1992-01-01	11.866
1992-04-01	12.656
1992-07-01	13.516
1992-10-01	12.931
1993-01-01	14.183
1993-04-01	16.105
1993-07-01	20.098
1993-10-01	21.133
1994-01-01	23.702
1994-04-01	26.081
1994-07-01	27.970
1994-10-01	28.837
1995-01-01	30.231
1995-04-01	31.629
1995-07-01	32.001
1995-10-01	32.164
1996-01-01	31.241
1996-04-01	32.424
1996-07-01	34.724
1996-10-01	34.942
1997-01-01	34.938
1997-04-01	39.025
1997-07-01	40.815
1997-10-01	39.203
1998-01-01	39.175
1998-04-01	39.491
1998-07-01	40.544
1998-10-01	41.419
1999-01-01	38.746
1999-04-01	37.209
1999-07-01	37.164
1999-10-01	36.588
2000-01-01	35.415
2000-04-01	34.656
2000-07-01	31.879
2000-10-01	32.567
2001-01-01	30.978
2001-04-01	30.534
2001-07-01	30.381
2001-10-01	29.970
2002-01-01	28.694
2002-04-01	34.370
2002-07-01	35.439
2002-10-01	38.686
2003-01-01	38.529
2003-04-01	38.605
2003-07-01	40.007
2003-10-01	41.019
2004-01-01	38.695
2004-04-01	39.345
2004-07-01	39.349
2004-10-01	42.448
2005-01-01	43.184
2005-04-01	46.044
2005-07-01	46.271
2005-10-01	45.506
2006-01-01	53.776
2006-04-01	54.937
2006-07-01	55.996
2006-10-01	68.996
2007-01-01	72.074
2007-04-01	76.215
2007-07-01	79.015
2007-10-01	81.158
2008-01-01	80.282
2008-04-01	85.143
2008-07-01	84.655
2008-10-01	83.085
2009-01-01	81.042
2009-04-01	79.227
2009-07-01	85.080
2009-10-01	84.965
2010-01-01	85.319
2010-04-01	84.352
2010-07-01	93.573
2010-10-01	93.314
2011-01-01	98.570
2011-04-01	102.344
2011-07-01	101.194
2011-10-01	100.796
2012-01-01	105.475
2012-04-01	106.215
2012-07-01	109.643
2012-10-01	122.542
2013-01-01	123.074
2013-04-01	131.534
2013-07-01	135.493
2013-10-01	138.436
2014-01-01	143.547
2014-04-01	150.657
2014-07-01	151.840
2014-10-01	153.914
2015-01-01	157.466
2015-04-01	170.623