Quarter	US dollars
1999-03-31	50733
1999-06-30	60433
1999-09-30	60647
1999-12-31	59517
2000-03-31	63836
2000-06-30	65874
2000-09-30	61410
2000-12-31	65618
2001-03-31	62773
2001-06-30	63438
2001-09-30	61399
2001-12-31	55590
2002-03-31	54241
2002-06-30	66581
2002-09-30	67504
2002-12-31	72014
2003-03-31	74997
2003-06-30	79170
2003-09-30	77920
2003-12-31	70042
2004-03-31	67069
2004-06-30	68051
2004-09-30	65397
2004-12-31	64162
2005-03-31	58145
2005-06-30	67268
2005-09-30	58376
2005-12-31	48858
2006-03-31	55897
2006-06-30	49273
2006-09-30	44168
2006-12-31	54111
2007-03-31	49351
2007-06-30	55477
2007-09-30	57011
2007-12-31	49958
2008-03-31	54651
2008-06-30	49801
2008-09-30	50921
2008-12-31	43461
2009-03-31	48151
2009-06-30	49031
2009-09-30	52724
2009-12-31	48524
2010-03-31	42541
2010-06-30	41494
2010-09-30	39569
2010-12-31	39274
2011-03-31	46599
2011-06-30	57786
2011-09-30	36688
2011-12-31	32996
2012-03-31	33078
2012-06-30	31666
2012-09-30	31124
2012-12-31	33077
2013-03-31	27955
2013-06-30	27766
2013-09-30	26695
2013-12-31	25584
2014-03-31	30391
2014-06-30	30992
2014-09-30	30377
2014-12-31	26919
2015-03-31	27015
2015-06-30	16277
2015-09-30	23457
2015-12-31	24162
2016-03-31	27531
2016-06-30	17423
2016-09-30	11909
2016-12-31	10992
2017-03-31	10525
2017-06-30	13980
2017-09-30	14775
2017-12-31	11698
2018-03-31	15739
2018-06-30	14453
2018-09-30	14440
2018-12-31	15468
2019-03-31	19650
2019-06-30	19923
2019-09-30	19981
2019-12-31	18644
2020-03-31	21672
2020-06-30	20937
2020-09-30	20623
2020-12-31	20694
2021-03-31	17327
2021-06-30	15350
2021-09-30	14926
2021-12-31	13403
2022-03-31	11350
2022-06-30	13614
2022-09-30	12396
2022-12-31	15236
2023-03-31	13561
2023-06-30	13065
2023-09-30	13262