Quarter	US dollars
1999-03-31	6244
1999-06-30	7208
1999-09-30	9124
1999-12-31	7738
2000-03-31	9997
2000-06-30	4362
2000-09-30	7007
2000-12-31	8742
2001-03-31	9114
2001-06-30	9412
2001-09-30	10631
2001-12-31	11382
2002-03-31	9504
2002-06-30	12370
2002-09-30	10841
2002-12-31	10538
2003-03-31	15058
2003-06-30	16194
2003-09-30	13847
2003-12-31	11245
2004-03-31	16481
2004-06-30	15081
2004-09-30	13378
2004-12-31	13835
2005-03-31	16354
2005-06-30	16697
2005-09-30	13722
2005-12-31	8311
2006-03-31	7020
2006-06-30	6758
2006-09-30	12004
2006-12-31	17300
2007-03-31	15707
2007-06-30	19104
2007-09-30	20959
2007-12-31	21037
2008-03-31	20373
2008-06-30	21113
2008-09-30	19296
2008-12-31	32281
2009-03-31	33060
2009-06-30	29362
2009-09-30	32210
2009-12-31	24593
2010-03-31	25370
2010-06-30	19201
2010-09-30	25576
2010-12-31	18026
2011-03-31	25457
2011-06-30	21005
2011-09-30	22825
2011-12-31	23492
2012-03-31	18529
2012-06-30	18898
2012-09-30	18517
2012-12-31	17383
2013-03-31	19555
2013-06-30	18596
2013-09-30	16429
2013-12-31	14740
2014-03-31	19109
2014-06-30	23401
2014-09-30	17224
2014-12-31	14183
2015-03-31	15622
2015-06-30	16131
2015-09-30	14502
2015-12-31	16823
2016-03-31	15071
2016-06-30	14023
2016-09-30	13850
2016-12-31	15896
2017-03-31	16525
2017-06-30	12572
2017-09-30	14655
2017-12-31	14412
2018-03-31	18720
2018-06-30	21498
2018-09-30	13843
2018-12-31	12078
2019-03-31	16869
2019-06-30	12635
2019-09-30	15418
2019-12-31	13051
2020-03-31	17756
2020-06-30	13955
2020-09-30	12682
2020-12-31	14299
2021-03-31	12811
2021-06-30	11207
2021-09-30	10367
2021-12-31	10696
2022-03-31	9405
2022-06-30	9238
2022-09-30	9603
2022-12-31	7634
2023-03-31	9541
2023-06-30	10315
2023-09-30	10640