Quarter	US dollars
1999-03-31	28220
1999-06-30	26554
1999-09-30	26550
1999-12-31	27042
2000-03-31	27708
2000-06-30	25380
2000-09-30	24460
2000-12-31	24630
2001-03-31	24534
2001-06-30	23530
2001-09-30	22991
2001-12-31	23851
2002-03-31	23586
2002-06-30	23297
2002-09-30	21334
2002-12-31	22650
2003-03-31	20211
2003-06-30	19576
2003-09-30	21119
2003-12-31	19160
2004-03-31	23964
2004-06-30	19493
2004-09-30	18984
2004-12-31	20046
2005-03-31	18242
2005-06-30	19351
2005-09-30	21866
2005-12-31	21871
2006-03-31	27816
2006-06-30	29145
2006-09-30	34596
2006-12-31	30954
2007-03-31	32885
2007-06-30	39119
2007-09-30	36378
2007-12-31	35929
2008-03-31	37958
2008-06-30	40130
2008-09-30	37754
2008-12-31	25618
2009-03-31	27151
2009-06-30	27981
2009-09-30	28624
2009-12-31	29637
2010-03-31	31700
2010-06-30	30975
2010-09-30	40160
2010-12-31	41332
2011-03-31	43773
2011-06-30	48457
2011-09-30	43529
2011-12-31	46659
2012-03-31	55588
2012-06-30	47056
2012-09-30	45864
2012-12-31	47258
2013-03-31	47890
2013-06-30	44589
2013-09-30	51089
2013-12-31	53410
2014-03-31	45474
2014-06-30	44685
2014-09-30	42553
2014-12-31	42646
2015-03-31	43822
2015-06-30	44069
2015-09-30	42070
2015-12-31	42780
2016-03-31	30181
2016-06-30	29130
2016-09-30	27456
2016-12-31	24370
2017-03-31	24861
2017-06-30	22466
2017-09-30	25310
2017-12-31	23757
2018-03-31	24158
2018-06-30	22539
2018-09-30	25502
2018-12-31	27436
2019-03-31	27518
2019-06-30	27582
2019-09-30	29298
2019-12-31	25809
2020-03-31	25437
2020-06-30	22136
2020-09-30	19779
2020-12-31	30694
2021-03-31	27845
2021-06-30	27518
2021-09-30	26479
2021-12-31	42299
2022-03-31	39659
2022-06-30	28803
2022-09-30	43585
2022-12-31	48195
2023-03-31	51408
2023-06-30	55584
2023-09-30	36737