Quarter	US dollars
1999-03-31	8400
1999-06-30	12695
1999-09-30	13729
1999-12-31	14508
2000-03-31	17059
2000-06-30	12882
2000-09-30	12923
2000-12-31	16759
2001-03-31	14489
2001-06-30	12493
2001-09-30	15756
2001-12-31	17678
2002-03-31	19314
2002-06-30	19383
2002-09-30	19605
2002-12-31	21661
2003-03-31	21066
2003-06-30	29096
2003-09-30	27059
2003-12-31	27661
2004-03-31	32055
2004-06-30	32353
2004-09-30	28211
2004-12-31	27862
2005-03-31	25683
2005-06-30	26751
2005-09-30	25411
2005-12-31	25804
2006-03-31	30881
2006-06-30	31116
2006-09-30	34027
2006-12-31	34493
2007-03-31	35332
2007-06-30	38182
2007-09-30	43262
2007-12-31	45890
2008-03-31	52766
2008-06-30	56883
2008-09-30	59830
2008-12-31	48687
2009-03-31	55800
2009-06-30	58838
2009-09-30	60073
2009-12-31	60987
2010-03-31	46012
2010-06-30	54072
2010-09-30	46081
2010-12-31	50456
2011-03-31	52383
2011-06-30	58898
2011-09-30	69868
2011-12-31	54328
2012-03-31	62063
2012-06-30	59689
2012-09-30	61880
2012-12-31	62844
2013-03-31	55517
2013-06-30	51919
2013-09-30	53695
2013-12-31	65393
2014-03-31	59380
2014-06-30	60907
2014-09-30	61264
2014-12-31	60344
2015-03-31	50185
2015-06-30	48908
2015-09-30	51759
2015-12-31	47653
2016-03-31	42614
2016-06-30	44927
2016-09-30	44037
2016-12-31	49276
2017-03-31	39297
2017-06-30	34417
2017-09-30	29714
2017-12-31	30663
2018-03-31	32768
2018-06-30	30635
2018-09-30	30357
2018-12-31	38082
2019-03-31	29493
2019-06-30	33796
2019-09-30	32545
2019-12-31	34489
2020-03-31	44110
2020-06-30	35655
2020-09-30	38665
2020-12-31	54261
2021-03-31	36946
2021-06-30	41147
2021-09-30	40103
2021-12-31	52333
2022-03-31	49916
2022-06-30	46719
2022-09-30	45074
2022-12-31	44926
2023-03-31	46151
2023-06-30	36250
2023-09-30	37856