Quarter	Millions of US Dollars
2001-10-01	9588
2002-01-01	10154
2002-04-01	16826
2002-07-01	19951
2002-10-01	17753
2003-01-01	17477
2003-04-01	18276
2003-07-01	22119
2003-10-01	23928
2004-01-01	22245
2004-04-01	24311
2004-07-01	29335
2004-10-01	28185
2005-01-01	23307
2005-04-01	22145
2005-07-01	24971
2005-10-01	27086
2006-01-01	29670
2006-04-01	33034
2006-07-01	31243
2006-10-01	34432
2007-01-01	28905
2007-04-01	36155
2007-07-01	48514
2007-10-01	55400
2008-01-01	51778
2008-04-01	47713
2008-07-01	34729
2008-10-01	41039
2009-01-01	54935
2009-04-01	39004
2009-07-01	64701
2009-10-01	54604
2010-01-01	34731
2010-04-01	18755
2010-07-01	25385
2010-10-01	8458
2011-01-01	7425
2011-04-01	8748
2011-07-01	11515
2011-10-01	11924
2012-01-01	13513
2012-04-01	11839
2012-07-01	13743
2012-10-01	12568
2013-01-01	5875
2013-04-01	7133
2013-07-01	10180
2013-10-01	7986
2014-01-01	8678
2014-04-01	11599
2014-07-01	13448
2014-10-01	8968
2015-01-01	11418
2015-04-01	11302
2015-07-01	12785
2015-10-01	18259
2016-01-01	28203
2016-04-01	25011
2016-07-01	21092
2016-10-01	25549
2017-01-01	34818
2017-04-01	34389
2017-07-01	37630
2017-10-01	48649
2018-01-01	36025