Quarter	US dollars
1997-09-30	14045
1997-12-31	15409
1998-03-31	19507
1998-06-30	21900
1998-09-30	25213
1998-12-31	25093
1999-03-31	25209
1999-06-30	26081
1999-09-30	27064
1999-12-31	26345
2000-03-31	26073
2000-06-30	25088
2000-09-30	25203
2000-12-31	27259
2001-03-31	24567
2001-06-30	24143
2001-09-30	23340
2001-12-31	19879
2002-03-31	19401
2002-06-30	21095
2002-09-30	21873
2002-12-31	21683
2003-03-31	20925
2003-06-30	22982
2003-09-30	24094
2003-12-31	26427
2004-03-31	28359
2004-06-30	29963
2004-09-30	28252
2004-12-31	33700
2005-03-31	34012
2005-06-30	32997
2005-09-30	31888
2005-12-31	32673
2006-03-31	37478
2006-06-30	40396
2006-09-30	42372
2006-12-31	48193
2007-03-31	50402
2007-06-30	57086
2007-09-30	61652
2007-12-31	55306
2008-03-31	54932
2008-06-30	56129
2008-09-30	44105
2008-12-31	39166
2009-03-31	49303
2009-06-30	56634
2009-09-30	54168
2009-12-31	53560
2010-03-31	47329
2010-06-30	47325
2010-09-30	50941
2010-12-31	51172
2011-03-31	53212
2011-06-30	52572
2011-09-30	50886
2011-12-31	49792
2012-03-31	48342
2012-06-30	44921
2012-09-30	45479
2012-12-31	45636
2013-03-31	44383
2013-06-30	41290
2013-09-30	42415
2013-12-31	39865
2014-03-31	41922
2014-06-30	43116
2014-09-30	39647
2014-12-31	37861
2015-03-31	37029
2015-06-30	39305
2015-09-30	37415
2015-12-31	36608
2016-03-31	35916
2016-06-30	34458
2016-09-30	34613
2016-12-31	29145
2017-03-31	26456
2017-06-30	24561
2017-09-30	25252
2017-12-31	25571
2018-03-31	27567
2018-06-30	25476
2018-09-30	25568
2018-12-31	21957
2019-03-31	21514
2019-06-30	20881
2019-09-30	20784
2019-12-31	20487
2020-03-31	19743
2020-06-30	19453
2020-09-30	19404
2020-12-31	20984
2021-03-31	20832
2021-06-30	20256
2021-09-30	20476
2021-12-31	20740
2022-03-31	20562
2022-06-30	19776
2022-09-30	19136
2022-12-31	20301
2023-03-31	20933
2023-06-30	21873
2023-09-30	21783