Quarter	Millions of US Dollars
2001-01-01	7627
2001-04-01	7765
2001-07-01	7007
2001-10-01	5556
2002-01-01	6072
2002-04-01	6387
2002-07-01	6523
2002-10-01	7756
2003-01-01	8606
2003-04-01	9077
2003-07-01	10024
2003-10-01	11072
2004-01-01	11228
2004-04-01	11420
2004-07-01	11905
2004-10-01	14169
2005-01-01	12892
2005-04-01	12853
2005-07-01	13350
2005-10-01	13006
2006-01-01	13349
2006-04-01	12068
2006-07-01	12299
2006-10-01	14117
2007-01-01	14126
2007-04-01	14821
2007-07-01	15253
2007-10-01	16333
2008-01-01	13330
2008-04-01	13500
2008-07-01	15039
2008-10-01	14159
2009-01-01	15017
2009-04-01	19424
2009-07-01	21845
2009-10-01	23167
2010-01-01	24587
2010-04-01	24649
2010-07-01	28183
2010-10-01	30782
2011-01-01	30185
2011-04-01	30708
2011-07-01	25748
2011-10-01	25843
2012-01-01	27610
2012-04-01	26726
2012-07-01	27358
2012-10-01	27846
2013-01-01	26584
2013-04-01	25413
2013-07-01	25847
2013-10-01	25429
2014-01-01	25416
2014-04-01	26122
2014-07-01	24441
2014-10-01	24435
2015-01-01	23622
2015-04-01	24420
2015-07-01	21379
2015-10-01	19243
2016-01-01	20421
2016-04-01	20393
2016-07-01	22437
2016-10-01	22595
2017-01-01	23511
2017-04-01	24118
2017-07-01	23716
2017-10-01	25679
2018-01-01	26782