Quarter	Billions of US Dollars
1987-01-01	8.017
1987-04-01	8.578
1987-07-01	9.157
1987-10-01	9.754
1988-01-01	9.910
1988-04-01	10.567
1988-07-01	11.474
1988-10-01	12.596
1989-01-01	13.055
1989-04-01	13.430
1989-07-01	14.423
1989-10-01	15.027
1990-01-01	15.069
1990-04-01	15.053
1990-07-01	15.314
1990-10-01	15.219
1991-01-01	14.117
1991-04-01	13.768
1991-07-01	13.517
1991-10-01	13.461
1992-01-01	12.833
1992-04-01	12.942
1992-07-01	12.875
1992-10-01	11.514
1993-01-01	11.912
1993-04-01	10.737
1993-07-01	12.211
1993-10-01	12.173
1994-01-01	12.305
1994-04-01	13.170
1994-07-01	12.825
1994-10-01	12.353
1995-01-01	12.607
1995-04-01	12.813
1995-07-01	12.720
1995-10-01	13.457
1996-01-01	12.903
1996-04-01	14.507
1996-07-01	15.081
1996-10-01	14.883
1997-01-01	15.626
1997-04-01	17.551
1997-07-01	17.781
1997-10-01	17.912
1998-01-01	18.777
1998-04-01	20.440
1998-07-01	20.000
1998-10-01	19.946
1999-01-01	21.150
1999-04-01	24.519
1999-07-01	23.734
1999-10-01	24.736
2000-01-01	26.602
2000-04-01	25.552
2000-07-01	25.211
2000-10-01	25.976
2001-01-01	25.354
2001-04-01	26.081
2001-07-01	26.088
2001-10-01	28.092
2002-01-01	31.889
2002-04-01	39.588
2002-07-01	44.864
2002-10-01	48.707
2003-01-01	51.585
2003-04-01	60.153
2003-07-01	66.000
2003-10-01	77.792
2004-01-01	79.427
2004-04-01	74.566
2004-07-01	82.309
2004-10-01	89.922
2005-01-01	89.057
2005-04-01	90.659
2005-07-01	95.518
2005-10-01	100.240
2006-01-01	106.656
2006-04-01	111.810
2006-07-01	118.185
2006-10-01	123.849
2007-01-01	127.254
2007-04-01	144.901
2007-07-01	154.587
2007-10-01	165.748
2008-01-01	167.405
2008-04-01	188.092
2008-07-01	180.221
2008-10-01	159.869
2009-01-01	166.978
2009-04-01	193.536
2009-07-01	207.569
2009-10-01	226.263
2010-01-01	230.364
2010-04-01	230.737
2010-07-01	240.111
2010-10-01	254.705
2011-01-01	260.640
2011-04-01	278.394
2011-07-01	251.900
2011-10-01	257.235
2012-01-01	268.234
2012-04-01	246.017
2012-07-01	255.384
2012-10-01	242.437
2013-01-01	241.876
2013-04-01	215.413
2013-07-01	228.478
2013-10-01	225.097
2014-01-01	212.039
2014-04-01	213.499
2014-07-01	198.608
2014-10-01	185.918
2015-01-01	172.421
2015-04-01	171.001