Quarter	Millions of US Dollars
2008-01-01	43969
2008-04-01	39341
2008-07-01	40402
2008-10-01	34975
2009-01-01	38921
2009-04-01	42397
2009-07-01	40125
2009-10-01	42552
2010-01-01	40873
2010-04-01	41369
2010-07-01	48296
2010-10-01	48897
2011-01-01	50182
2011-04-01	55928
2011-07-01	55156
2011-10-01	57214
2012-01-01	61937
2012-04-01	62018
2012-07-01	68566
2012-10-01	66722
2013-01-01	68154
2013-04-01	66013
2013-07-01	68747
2013-10-01	67695
2014-01-01	63557
2014-04-01	67744
2014-07-01	63564
2014-10-01	64554
2015-01-01	63855
2015-04-01	64933
2015-07-01	60721
2015-10-01	58832
2016-01-01	61593
2016-04-01	66103
2016-07-01	69854