Quarter	Billions of US Dollars
1998-01-01	82.950
1998-04-01	84.871
1998-07-01	86.159
1998-10-01	86.471
1999-01-01	87.372
1999-04-01	86.458
1999-07-01	87.255
1999-10-01	89.458
2000-01-01	93.508
2000-04-01	91.580
2000-07-01	91.212
2000-10-01	94.210
2001-01-01	94.231
2001-04-01	92.887
2001-07-01	89.672
2001-10-01	92.614
2002-01-01	92.893
2002-04-01	92.522
2002-07-01	90.808
2002-10-01	93.552
2003-01-01	93.727
2003-04-01	96.476
2003-07-01	100.918
2003-10-01	109.842
2004-01-01	109.631
2004-04-01	109.249
2004-07-01	116.329
2004-10-01	123.927
2005-01-01	123.029
2005-04-01	127.458
2005-07-01	137.579
2005-10-01	143.955
2006-01-01	143.221
2006-04-01	142.556
2006-07-01	149.355
2006-10-01	154.489
2007-01-01	157.839
2007-04-01	163.751
2007-07-01	175.442
2007-10-01	187.758
2008-01-01	211.592
2008-04-01	191.921
2008-07-01	192.936
2008-10-01	181.300
2009-01-01	194.365
2009-04-01	207.383
2009-07-01	207.508
2009-10-01	225.545
2010-01-01	223.343
2010-04-01	225.897
2010-07-01	253.298
2010-10-01	268.237
2011-01-01	270.569
2011-04-01	285.919
2011-07-01	277.697
2011-10-01	286.672
2012-01-01	309.135
2012-04-01	311.107
2012-07-01	342.609
2012-10-01	352.982
2013-01-01	361.508
2013-04-01	353.036
2013-07-01	363.208
2013-10-01	364.437
2014-01-01	358.900
2014-04-01	369.879
2014-07-01	356.466
2014-10-01	373.706
2015-01-01	369.946
2015-04-01	376.665
2015-07-01	367.549
2015-10-01	372.865
2016-01-01	393.636
2016-04-01	408.525
2016-07-01	419.719
2016-10-01	423.810
2017-01-01	430.398
2017-04-01	441.174
2017-07-01	459.181
2017-10-01	477.291
2018-01-01	489.887