Quarter	Billions of US Dollars
1988-04-01	70.694
1988-07-01	69.616
1988-10-01	71.947
1989-01-01	68.026
1989-04-01	62.695
1989-07-01	63.082
1989-10-01	63.035
1990-01-01	61.940
1990-04-01	65.568
1990-07-01	67.519
1990-10-01	63.621
1991-01-01	65.351
1991-04-01	71.190
1991-07-01	78.875
1991-10-01	77.096
1992-01-01	80.685
1992-04-01	80.860
1992-07-01	81.864
1992-10-01	83.841
1993-01-01	91.084
1993-04-01	91.866
1993-07-01	92.469
1993-10-01	101.241
1994-01-01	106.169
1994-04-01	112.500
1994-07-01	116.774
1994-10-01	124.727
1995-01-01	119.320
1995-04-01	120.201
1995-07-01	127.928
1995-10-01	126.881
1996-01-01	132.560
1996-04-01	130.840
1996-07-01	130.806
1996-10-01	131.617
1997-01-01	129.190
1997-04-01	121.377
1997-07-01	114.286
1997-10-01	99.808
1998-01-01	99.055
1998-04-01	89.450
1998-07-01	84.841
1998-10-01	85.737
1999-01-01	85.013
1999-04-01	88.273
1999-07-01	84.890
1999-10-01	82.417
2000-01-01	73.519
2000-04-01	72.243
2000-07-01	62.122
2000-10-01	61.585
2001-01-01	52.714
2001-04-01	54.374
2001-07-01	53.018
2001-10-01	54.048
2002-01-01	55.334
2002-04-01	58.373
2002-07-01	55.529
2002-10-01	56.523
2003-01-01	59.210
2003-04-01	64.981
2003-07-01	65.504
2003-10-01	71.098
2004-01-01	71.148
2004-04-01	63.547
2004-07-01	66.994
2004-10-01	71.882
2005-01-01	70.796
2005-04-01	69.339
2005-07-01	69.057
2005-10-01	65.465
2006-01-01	63.064
2006-04-01	65.262
2006-07-01	66.172
2006-10-01	68.924
2007-01-01	69.338
2007-04-01	75.109
2007-07-01	81.589
2007-10-01	81.105
2008-01-01	84.959
2008-04-01	99.186
2008-07-01	92.846
2008-10-01	88.961
2009-01-01	97.926
2009-04-01	124.596
2009-07-01	154.886
2009-10-01	167.855
2010-01-01	186.016
2010-04-01	186.851
2010-07-01	226.920
2010-10-01	246.974
2011-01-01	269.500
2011-04-01	302.574
2011-07-01	294.776
2011-10-01	323.512
2012-01-01	343.795
2012-04-01	362.264
2012-07-01	383.020
2012-10-01	389.741
2013-01-01	398.765
2013-04-01	361.877
2013-07-01	385.111
2013-10-01	385.734
2014-01-01	414.276
2014-04-01	439.431
2014-07-01	420.627
2014-10-01	407.846
2015-01-01	390.105
2015-04-01	401.092
2015-07-01	380.531
2015-10-01	402.130
2016-01-01	434.638
2016-04-01	427.271
2016-07-01	455.706
2016-10-01	440.238
2017-01-01	481.041
2017-04-01	498.392
2017-07-01	518.156
2017-10-01	527.281
2018-01-01	524.806