Quarter	Millions of US Dollars
2004-01-01	10325
2004-04-01	11245
2004-07-01	12384
2004-10-01	13665
2005-01-01	13982
2005-04-01	14967
2005-07-01	15653
2005-10-01	14855
2006-01-01	16940
2006-04-01	18075
2006-07-01	18329
2006-10-01	20161
2007-01-01	21961
2007-04-01	22895
2007-07-01	21035
2007-10-01	21888
2008-01-01	22514
2008-04-01	21206
2008-07-01	26134
2008-10-01	20875
2009-01-01	19706
2009-04-01	23854
2009-07-01	24504
2009-10-01	20804
2010-01-01	21535
2010-04-01	19180
2010-07-01	16716
2010-10-01	17334
2011-01-01	19040
2011-04-01	21872
2011-07-01	22503
2011-10-01	23704
2012-01-01	21663
2012-04-01	21808
2012-07-01	22458
2012-10-01	24465
2013-01-01	23629
2013-04-01	20154
2013-07-01	21175
2013-10-01	21863
2014-01-01	21460
2014-04-01	22311
2014-07-01	18567
2014-10-01	18433
2015-01-01	16382
2015-04-01	17639
2015-07-01	16827
2015-10-01	15085
2016-01-01	15832
2016-04-01	16046
2016-07-01	18032
2016-10-01	18318
2017-01-01	19635
2017-04-01	22956
2017-07-01	20043
2017-10-01	21885
2018-01-01	21008