Quarter	Billions of US Dollars
1997-01-01	0.3501
1997-04-01	0.4056
1997-07-01	2.0365
1997-10-01	2.0326
1998-01-01	2.1205
1998-04-01	2.1264
1998-07-01	2.1546
1998-10-01	2.1063
1999-01-01	2.4007
1999-04-01	2.3761
1999-07-01	2.4292
1999-10-01	2.6351
2000-01-01	3.0735
2000-04-01	3.0749
2000-07-01	3.3513
2000-10-01	3.3751
2001-01-01	3.8790
2001-04-01	3.8281
2001-07-01	4.1853
2001-10-01	4.0569
2002-01-01	4.1701
2002-04-01	4.8219
2002-07-01	4.7781
2002-10-01	5.0443
2003-01-01	5.6876
2003-04-01	6.0563
2003-07-01	6.2138
2003-10-01	6.5519
2004-01-01	6.7949
2004-04-01	7.4511
2004-07-01	7.2900
2004-10-01	7.5793
2005-01-01	6.6560
2005-04-01	6.3492
2005-07-01	6.3079
2005-10-01	6.1885
2006-01-01	5.7148
2006-04-01	5.9065
2006-07-01	5.1666
2006-10-01	5.4996
2007-01-01	5.5516
2007-04-01	5.9097
2007-07-01	6.2550
2007-10-01	6.4487
2008-01-01	6.2317
2008-04-01	5.9503
2008-07-01	5.4017
2008-10-01	5.3024
2009-01-01	4.3642
2009-04-01	5.4172
2009-07-01	5.5691
2009-10-01	7.3404
2010-01-01	6.2566
2010-04-01	5.8338
2010-07-01	7.5268
2010-10-01	7.4267
2011-01-01	7.9438
2011-04-01	8.0078
2011-07-01	8.7735
2011-10-01	8.5846
2012-01-01	8.7243
2012-04-01	10.3454
2012-07-01	10.4695
2012-10-01	11.6627
2013-01-01	11.5119
2013-04-01	13.1185
2013-07-01	13.4858
2013-10-01	15.3509
2014-01-01	15.3497
2014-04-01	15.7754
2014-07-01	15.3051
2014-10-01	15.1117
2015-01-01	15.3140
2015-04-01	15.5344