Quarter	Millions of US Dollars
2005-01-01	17582
2005-04-01	23739
2005-07-01	24605
2005-10-01	23094
2006-01-01	28663
2006-04-01	29230
2006-07-01	32533
2006-10-01	35285
2007-01-01	40833
2007-04-01	42695
2007-07-01	38796
2007-10-01	39897
2008-01-01	46470
2008-04-01	48239
2008-07-01	41558
2008-10-01	32865
2009-01-01	28525
2009-04-01	30134
2009-07-01	25213
2009-10-01	22979
2010-01-01	21917
2010-04-01	31649
2010-07-01	35165
2010-10-01	37983
2011-01-01	42664
2011-04-01	45896
2011-07-01	49961
2011-10-01	42481
2012-01-01	51059
2012-04-01	47955
2012-07-01	51330
2012-10-01	49448
2013-01-01	44324
2013-04-01	41419
2013-07-01	38300
2013-10-01	37545
2014-01-01	35150
2014-04-01	34047
2014-07-01	42047
2014-10-01	47191
2015-01-01	33681
2015-04-01	21707
2015-07-01	16874
2015-10-01	18816
2016-01-01	18303
2016-04-01	15361
2016-07-01	14220
2016-10-01	13832
2017-01-01	12682
2017-04-01	12452
2017-07-01	12564
2017-10-01	14859
2018-01-01	15021