Quarter	Billions of US Dollars
1987-01-01	8.544
1987-04-01	8.608
1987-07-01	8.658
1987-10-01	9.681
1988-01-01	9.851
1988-04-01	9.706
1988-07-01	9.891
1988-10-01	10.510
1989-01-01	10.682
1989-04-01	10.317
1989-07-01	10.987
1989-10-01	11.845
1990-01-01	11.841
1990-04-01	12.862
1990-07-01	14.175
1990-10-01	14.033
1991-01-01	13.865
1991-04-01	13.491
1991-07-01	14.592
1991-10-01	15.275
1992-01-01	14.947
1992-04-01	16.018
1992-07-01	17.711
1992-10-01	15.780
1993-01-01	15.314
1993-04-01	15.400
1993-07-01	15.407
1993-10-01	15.227
1994-01-01	15.477
1994-04-01	15.273
1994-07-01	15.836
1994-10-01	16.303
1995-01-01	18.528
1995-04-01	18.790
1995-07-01	18.712
1995-10-01	19.079
1996-01-01	19.372
1996-04-01	19.843
1996-07-01	20.346
1996-10-01	20.107
1997-01-01	20.028
1997-04-01	20.669
1997-07-01	21.535
1997-10-01	21.048
1998-01-01	22.349
1998-04-01	23.243
1998-07-01	24.525
1998-10-01	25.571
1999-01-01	25.008
1999-04-01	26.339
1999-07-01	28.580
1999-10-01	29.630
2000-01-01	30.907
2000-04-01	34.223
2000-07-01	37.002
2000-10-01	38.799
2001-01-01	40.512
2001-04-01	40.797
2001-07-01	43.373
2001-10-01	44.291
2002-01-01	47.754
2002-04-01	56.354
2002-07-01	55.543
2002-10-01	58.562
2003-01-01	61.222
2003-04-01	65.334
2003-07-01	69.240
2003-10-01	73.994
2004-01-01	79.656
2004-04-01	80.441
2004-07-01	83.207
2004-10-01	90.237
2005-01-01	95.446
2005-04-01	93.320
2005-07-01	94.602
2005-10-01	98.038
2006-01-01	104.660
2006-04-01	114.346
2006-07-01	115.511
2006-10-01	128.686
2007-01-01	146.876
2007-04-01	150.656
2007-07-01	156.467
2007-10-01	168.353
2008-01-01	185.467
2008-04-01	181.594
2008-07-01	171.635
2008-10-01	170.636
2009-01-01	163.943
2009-04-01	174.791
2009-07-01	180.893
2009-10-01	172.756
2010-01-01	162.111
2010-04-01	148.193
2010-07-01	164.701
2010-10-01	159.797
2011-01-01	167.208
2011-04-01	163.695
2011-07-01	158.838
2011-10-01	147.780
2012-01-01	145.058
2012-04-01	132.846
2012-07-01	135.248
2012-10-01	138.084
2013-01-01	128.341
2013-04-01	130.793
2013-07-01	126.572
2013-10-01	130.908
2014-01-01	121.675
2014-04-01	117.534
2014-07-01	106.805
2014-10-01	103.475
2015-01-01	95.035
2015-04-01	94.244