Quarter	Billions of US Dollars
1987-01-01	1.187
1987-04-01	1.463
1987-07-01	1.951
1987-10-01	2.123
1988-01-01	5.406
1988-04-01	6.585
1988-07-01	7.140
1988-10-01	7.660
1989-01-01	8.044
1989-04-01	8.174
1989-07-01	9.762
1989-10-01	8.814
1990-01-01	10.423
1990-04-01	10.803
1990-07-01	13.343
1990-10-01	14.990
1991-01-01	18.072
1991-04-01	18.258
1991-07-01	18.219
1991-10-01	19.165
1992-01-01	21.401
1992-04-01	21.361
1992-07-01	21.167
1992-10-01	19.471
1993-01-01	13.954
1993-04-01	13.226
1993-07-01	6.749
1993-10-01	5.880
1994-01-01	6.502
1994-04-01	6.274
1994-07-01	7.504
1994-10-01	8.190
1995-01-01	8.425
1995-04-01	7.536
1995-07-01	10.151
1995-10-01	10.630
1996-01-01	12.199
1996-04-01	11.995
1996-07-01	13.003
1996-10-01	11.452
1997-01-01	14.219
1997-04-01	14.531
1997-07-01	16.306
1997-10-01	18.295
1998-01-01	21.236
1998-04-01	23.901
1998-07-01	24.791
1998-10-01	24.873
1999-01-01	26.810
1999-04-01	28.585
1999-07-01	37.977
1999-10-01	39.680
2000-01-01	44.653
2000-04-01	49.339
2000-07-01	51.305
2000-10-01	54.512
2001-01-01	50.753
2001-04-01	45.189
2001-07-01	42.594
2001-10-01	45.148
2002-01-01	48.545
2002-04-01	52.521
2002-07-01	66.661
2002-10-01	57.921
2003-01-01	68.016
2003-04-01	78.124
2003-07-01	81.617
2003-10-01	89.151
2004-01-01	92.740
2004-04-01	91.685
2004-07-01	102.170
2004-10-01	112.016
2005-01-01	107.939
2005-04-01	110.195
2005-07-01	126.059
2005-10-01	115.864
2006-01-01	128.405
2006-04-01	125.266
2006-07-01	141.119
2006-10-01	163.017
2007-01-01	181.609
2007-04-01	182.337
2007-07-01	181.179
2007-10-01	181.877
2008-01-01	207.864
2008-04-01	208.580
2008-07-01	184.926
2008-10-01	190.883
2009-01-01	153.333
2009-04-01	142.633
2009-07-01	156.715
2009-10-01	116.001
2010-01-01	125.063
2010-04-01	110.322
2010-07-01	123.571
2010-10-01	96.851
2011-01-01	101.703
2011-04-01	103.218
2011-07-01	94.325
2011-10-01	83.770
2012-01-01	95.322
2012-04-01	84.400
2012-07-01	81.429
2012-10-01	64.535
2013-01-01	63.987
2013-04-01	53.037
2013-07-01	59.334
2013-10-01	59.697
2014-01-01	60.417
2014-04-01	59.653
2014-07-01	60.460
2014-10-01	59.905
2015-01-01	59.275
2015-04-01	58.632