Quarter	US dollars
1999-03-31	6745
1999-06-30	6670
1999-09-30	6955
1999-12-31	6799
2000-03-31	7111
2000-06-30	6866
2000-09-30	7443
2000-12-31	9588
2001-03-31	7935
2001-06-30	7181
2001-09-30	7982
2001-12-31	8222
2002-03-31	9456
2002-06-30	10196
2002-09-30	10762
2002-12-31	12181
2003-03-31	15963
2003-06-30	18637
2003-09-30	18846
2003-12-31	19206
2004-03-31	17818
2004-06-30	23022
2004-09-30	27242
2004-12-31	24806
2005-03-31	39371
2005-06-30	35641
2005-09-30	35396
2005-12-31	38183
2006-03-31	33418
2006-06-30	44402
2006-09-30	49508
2006-12-31	53699
2007-03-31	54476
2007-06-30	52609
2007-09-30	80411
2007-12-31	65899
2008-03-31	60021
2008-06-30	64151
2008-09-30	69249
2008-12-31	48765
2009-03-31	45266
2009-06-30	33239
2009-09-30	33025
2009-12-31	22333
2010-03-31	18696
2010-06-30	19395
2010-09-30	20042
2010-12-31	14017
2011-03-31	17990
2011-06-30	13022
2011-09-30	19191
2011-12-31	16731
2012-03-31	17249
2012-06-30	16463
2012-09-30	16150
2012-12-31	19669
2013-03-31	22212
2013-06-30	17539
2013-09-30	20032
2013-12-31	25349
2014-03-31	22680
2014-06-30	16851
2014-09-30	10741
2014-12-31	16993
2015-03-31	16478
2015-06-30	27093
2015-09-30	27519
2015-12-31	24453
2016-03-31	24997
2016-06-30	25037
2016-09-30	21198
2016-12-31	20709
2017-03-31	23992
2017-06-30	24496
2017-09-30	24290
2017-12-31	30261
2018-03-31	29346
2018-06-30	25561
2018-09-30	23980
2018-12-31	28071
2019-03-31	24723
2019-06-30	26688
2019-09-30	22925
2019-12-31	26907
2020-03-31	26192
2020-06-30	24936
2020-09-30	20486
2020-12-31	23623
2021-03-31	24206
2021-06-30	24421
2021-09-30	26437
2021-12-31	39900
2022-03-31	37599
2022-06-30	33021
2022-09-30	41951
2022-12-31	44948
2023-03-31	46645
2023-06-30	39005
2023-09-30	40696