Quarter	Millions of US Dollars
2002-04-01	245669
2002-07-01	235451
2002-10-01	245267
2003-01-01	224176
2003-04-01	233177
2003-07-01	223777
2003-10-01	218273
2004-01-01	216566
2004-04-01	210319
2004-07-01	203357
2004-10-01	224772
2005-01-01	224570
2005-04-01	225606
2005-07-01	222538
2005-10-01	222173
2006-01-01	219976
2006-04-01	222791
2006-07-01	219658
2006-10-01	223683
2007-01-01	223736
2007-04-01	228191
2007-07-01	229250
2007-10-01	223807
2008-01-01	222549
2008-04-01	211148
2008-07-01	187380
2008-10-01	183342
2009-01-01	202795
2009-04-01	240846
2009-07-01	277935
2009-10-01	294335
2010-01-01	315547
2010-04-01	309123
2010-07-01	348995
2010-10-01	364470
2011-01-01	387055
2011-04-01	408149
2011-07-01	380092
2011-10-01	399479
2012-01-01	421723
2012-04-01	432102
2012-07-01	466921
2012-10-01	500658
2013-01-01	492894
2013-04-01	491471
2013-07-01	530521
2013-10-01	554163
2014-01-01	545112
2014-04-01	574886
2014-07-01	551545
2014-10-01	499223
2015-01-01	491390
2015-04-01	514439
2015-07-01	488904
2015-10-01	489471
2016-01-01	506389
2016-04-01	501000
2016-07-01	523536
2016-10-01	478336
2017-01-01	516208
2017-04-01	515108
2017-07-01	512995
2017-10-01	549566
2018-01-01	552084