Quarter	Millions of US Dollars
1998-10-01	348
1999-01-01	525
1999-04-01	283
1999-07-01	403
1999-10-01	345
2000-01-01	310
2000-04-01	301
2000-07-01	279
2000-10-01	319
2001-01-01	311
2001-04-01	313
2001-07-01	362
2001-10-01	360
2002-01-01	343
2002-04-01	373
2002-07-01	425
2002-10-01	479
2003-01-01	634
2003-04-01	647
2003-07-01	757
2003-10-01	879
2004-01-01	877
2004-04-01	966
2004-07-01	1017
2004-10-01	1439
2005-01-01	1469
2005-04-01	1412
2005-07-01	1626
2005-10-01	1637
2006-01-01	1716
2006-04-01	1773
2006-07-01	1805
2006-10-01	1823
2007-01-01	1836
2007-04-01	1867
2007-07-01	2045
2007-10-01	2104
2008-01-01	2312
2008-04-01	2412
2008-07-01	2235
2008-10-01	2491
2009-01-01	2636
2009-04-01	2554
2009-07-01	5576
2009-10-01	5515
2010-01-01	5120
2010-04-01	5811
2010-07-01	6511
2010-10-01	6470
2011-01-01	7262
2011-04-01	6555
2011-07-01	5888
2011-10-01	5157
2012-01-01	4882
2012-04-01	4327
2012-07-01	3155
2012-10-01	3163
2013-01-01	3263
2013-04-01	2867
2013-07-01	2799
2013-10-01	2456
2014-01-01	2449
2014-04-01	2352
2014-07-01	2419
2014-10-01	2113
2015-01-01	1799
2015-04-01	1032
2015-07-01	1335
2015-10-01	1231
2016-01-01	950
2016-04-01	983
2016-07-01	941
2016-10-01	886
2017-01-01	890
2017-04-01	841
2017-07-01	546
2017-10-01	535
2018-01-01	549