Quarter	Billions of US Dollars
1987-01-01	0.401
1987-04-01	0.436
1987-07-01	0.544
1987-10-01	0.374
1988-01-01	0.565
1988-04-01	0.412
1988-07-01	0.348
1988-10-01	0.617
1989-01-01	0.725
1989-04-01	0.363
1989-07-01	0.590
1989-10-01	0.404
1990-01-01	0.369
1990-04-01	0.221
1990-07-01	0.318
1990-10-01	0.401
1991-01-01	0.190
1991-04-01	0.882
1991-07-01	1.089
1991-10-01	1.525
1992-01-01	1.886
1992-04-01	2.306
1992-07-01	2.414
1992-10-01	4.242
1993-01-01	3.029
1993-04-01	4.199
1993-07-01	0.965
1993-10-01	1.179
1994-01-01	1.470
1994-04-01	2.154
1994-07-01	2.484
1994-10-01	3.452
1995-01-01	3.938
1995-04-01	4.411
1995-07-01	4.874
1995-10-01	7.831
1996-01-01	7.488
1996-04-01	6.230
1996-07-01	3.547
1996-10-01	2.960
1997-01-01	3.503
1997-04-01	4.042
1997-07-01	3.075
1997-10-01	4.430
1998-01-01	6.156
1998-04-01	4.095
1998-07-01	4.157
1998-10-01	7.015
1999-01-01	11.862
1999-04-01	15.821
1999-07-01	26.633
1999-10-01	37.939
2000-01-01	47.871
2000-04-01	59.194
2000-07-01	61.249
2000-10-01	72.955
2001-01-01	62.784
2001-04-01	53.798
2001-07-01	51.395
2001-10-01	42.000
2002-01-01	40.379
2002-04-01	44.707
2002-07-01	52.528
2002-10-01	53.552
2003-01-01	74.837
2003-04-01	71.307
2003-07-01	56.306
2003-10-01	60.305
2004-01-01	55.778
2004-04-01	57.112
2004-07-01	57.547
2004-10-01	53.638
2005-01-01	58.062
2005-04-01	55.792
2005-07-01	47.270
2005-10-01	38.514
2006-01-01	50.183
2006-04-01	54.786
2006-07-01	53.599
2006-10-01	47.735
2007-01-01	57.734
2007-04-01	73.797
2007-07-01	95.075
2007-10-01	112.764
2008-01-01	137.499
2008-04-01	145.350
2008-07-01	124.257
2008-10-01	109.806
2009-01-01	89.293
2009-04-01	85.248
2009-07-01	83.088
2009-10-01	74.860
2010-01-01	77.329
2010-04-01	73.839
2010-07-01	71.667
2010-10-01	79.791
2011-01-01	97.686
2011-04-01	105.923
2011-07-01	132.322
2011-10-01	137.858
2012-01-01	135.629
2012-04-01	139.202
2012-07-01	114.980
2012-10-01	111.639
2013-01-01	116.728
2013-04-01	123.549
2013-07-01	126.440
2013-10-01	106.881
2014-01-01	117.480
2014-04-01	118.128
2014-07-01	123.220
2014-10-01	121.797
2015-01-01	132.461
2015-04-01	127.584