Quarter	US dollars
1999-03-31	22188
1999-06-30	25264
1999-09-30	25850
1999-12-31	29921
2000-03-31	26922
2000-06-30	22882
2000-09-30	21253
2000-12-31	24104
2001-03-31	30636
2001-06-30	27230
2001-09-30	31480
2001-12-31	33622
2002-03-31	33303
2002-06-30	27284
2002-09-30	37156
2002-12-31	30932
2003-03-31	35173
2003-06-30	36914
2003-09-30	41279
2003-12-31	34382
2004-03-31	40584
2004-06-30	42997
2004-09-30	43055
2004-12-31	36501
2005-03-31	39845
2005-06-30	37432
2005-09-30	35654
2005-12-31	30773
2006-03-31	37012
2006-06-30	41455
2006-09-30	40855
2006-12-31	35391
2007-03-31	29785
2007-06-30	37382
2007-09-30	39822
2007-12-31	51224
2008-03-31	54196
2008-06-30	57872
2008-09-30	54518
2008-12-31	47977
2009-03-31	38669
2009-06-30	33267
2009-09-30	31919
2009-12-31	35875
2010-03-31	34998
2010-06-30	55759
2010-09-30	61693
2010-12-31	65615
2011-03-31	67291
2011-06-30	75259
2011-09-30	83545
2011-12-31	79054
2012-03-31	72619
2012-06-30	75473
2012-09-30	71446
2012-12-31	73394
2013-03-31	79122
2013-06-30	68751
2013-09-30	72670
2013-12-31	82624
2014-03-31	92735
2014-06-30	86949
2014-09-30	91936
2014-12-31	81916
2015-03-31	76328
2015-06-30	70869
2015-09-30	65857
2015-12-31	72962
2016-03-31	55278
2016-06-30	54144
2016-09-30	54801
2016-12-31	50312
2017-03-31	47364
2017-06-30	52741
2017-09-30	61063
2017-12-31	65286
2018-03-31	72142
2018-06-30	68496
2018-09-30	57402
2018-12-31	62886
2019-03-31	63953
2019-06-30	70424
2019-09-30	64604
2019-12-31	72967
2020-03-31	56886
2020-06-30	55691
2020-09-30	59442
2020-12-31	66557
2021-03-31	66129
2021-06-30	69590
2021-09-30	63105
2021-12-31	66872
2022-03-31	78571
2022-06-30	77277
2022-09-30	78013
2022-12-31	83644
2023-03-31	87965
2023-06-30	83596
2023-09-30	67677