Quarter	US dollars
1999-03-31	11933
1999-06-30	12383
1999-09-30	11096
1999-12-31	11187
2000-03-31	11298
2000-06-30	12950
2000-09-30	11905
2000-12-31	11455
2001-03-31	12960
2001-06-30	13314
2001-09-30	12884
2001-12-31	11800
2002-03-31	14073
2002-06-30	16854
2002-09-30	16244
2002-12-31	22010
2003-03-31	16292
2003-06-30	15203
2003-09-30	16185
2003-12-31	15359
2004-03-31	15403
2004-06-30	19440
2004-09-30	19212
2004-12-31	22509
2005-03-31	18919
2005-06-30	17367
2005-09-30	19997
2005-12-31	29960
2006-03-31	31014
2006-06-30	32299
2006-09-30	35696
2006-12-31	36591
2007-03-31	34580
2007-06-30	38182
2007-09-30	69494
2007-12-31	74227
2008-03-31	71509
2008-06-30	112871
2008-09-30	123847
2008-12-31	97371
2009-03-31	96825
2009-06-30	100191
2009-09-30	81238
2009-12-31	77531
2010-03-31	92419
2010-06-30	87158
2010-09-30	96920
2010-12-31	87752
2011-03-31	85721
2011-06-30	84555
2011-09-30	80971
2011-12-31	75032
2012-03-31	84250
2012-06-30	74284
2012-09-30	70099
2012-12-31	68856
2013-03-31	62580
2013-06-30	62300
2013-09-30	60427
2013-12-31	62579
2014-03-31	45568
2014-06-30	44285
2014-09-30	45664
2014-12-31	38062
2015-03-31	43148
2015-06-30	38180
2015-09-30	30402
2015-12-31	34281
2016-03-31	36896
2016-06-30	40001
2016-09-30	40919
2016-12-31	40712
2017-03-31	46873
2017-06-30	31134
2017-09-30	32374
2017-12-31	31020
2018-03-31	30560
2018-06-30	39107
2018-09-30	31773
2018-12-31	38567
2019-03-31	24805
2019-06-30	29095
2019-09-30	33927
2019-12-31	31665
2020-03-31	25842
2020-06-30	26551
2020-09-30	25093
2020-12-31	24038
2021-03-31	24458
2021-06-30	29600
2021-09-30	29500
2021-12-31	28687
2022-03-31	27573
2022-06-30	29315
2022-09-30	27396
2022-12-31	22186
2023-03-31	19427
2023-06-30	19199
2023-09-30	19601