Quarter	Millions of US Dollars
2001-01-01	6313
2001-04-01	6934
2001-07-01	6559
2001-10-01	4723
2002-01-01	3974
2002-04-01	4278
2002-07-01	3868
2002-10-01	5078
2003-01-01	6150
2003-04-01	7536
2003-07-01	8434
2003-10-01	7445
2004-01-01	7537
2004-04-01	7345
2004-07-01	9414
2004-10-01	12419
2005-01-01	11671
2005-04-01	11456
2005-07-01	11579
2005-10-01	11054
2006-01-01	11675
2006-04-01	9817
2006-07-01	10453
2006-10-01	11823
2007-01-01	11904
2007-04-01	12977
2007-07-01	15284
2007-10-01	15527
2008-01-01	12504
2008-04-01	14169
2008-07-01	14333
2008-10-01	12896
2009-01-01	14577
2009-04-01	15764
2009-07-01	15426
2009-10-01	13736
2010-01-01	14045
2010-04-01	14618
2010-07-01	15602
2010-10-01	15211
2011-01-01	16925
2011-04-01	16500
2011-07-01	14158
2011-10-01	12758
2012-01-01	13659
2012-04-01	11890
2012-07-01	11480
2012-10-01	9516
2013-01-01	9613
2013-04-01	9058
2013-07-01	8660
2013-10-01	7010
2014-01-01	6794
2014-04-01	6162
2014-07-01	5954
2014-10-01	5684
2015-01-01	6354
2015-04-01	6179
2015-07-01	5146
2015-10-01	4334
2016-01-01	4189
2016-04-01	3868
2016-07-01	3913
2016-10-01	4087
2017-01-01	4232
2017-04-01	4767
2017-07-01	4684
2017-10-01	4868
2018-01-01	4551