Quarter	US dollars
1999-03-31	22153
1999-06-30	21786
1999-09-30	21727
1999-12-31	21819
2000-03-31	20508
2000-06-30	20559
2000-09-30	19754
2000-12-31	19821
2001-03-31	20462
2001-06-30	20655
2001-09-30	20283
2001-12-31	19586
2002-03-31	18879
2002-06-30	19909
2002-09-30	19579
2002-12-31	20121
2003-03-31	20489
2003-06-30	21687
2003-09-30	22647
2003-12-31	23680
2004-03-31	23551
2004-06-30	24699
2004-09-30	27018
2004-12-31	31211
2005-03-31	28442
2005-06-30	30753
2005-09-30	30770
2005-12-31	34192
2006-03-31	38670
2006-06-30	37310
2006-09-30	41663
2006-12-31	46416
2007-03-31	47715
2007-06-30	56879
2007-09-30	58726
2007-12-31	63759
2008-03-31	70073
2008-06-30	72830
2008-09-30	70685
2008-12-31	76543
2009-03-31	75204
2009-06-30	73393
2009-09-30	73590
2009-12-31	71297
2010-03-31	75855
2010-06-30	74830
2010-09-30	73821
2010-12-31	75056
2011-03-31	72851
2011-06-30	74358
2011-09-30	70815
2011-12-31	65090
2012-03-31	64485
2012-06-30	67234
2012-09-30	72307
2012-12-31	65871
2013-03-31	62957
2013-06-30	62561
2013-09-30	61623
2013-12-31	62884
2014-03-31	66670
2014-06-30	68365
2014-09-30	66723
2014-12-31	64524
2015-03-31	64723
2015-06-30	66824
2015-09-30	68010
2015-12-31	68994
2016-03-31	68775
2016-06-30	75920
2016-09-30	78320
2016-12-31	75869
2017-03-31	78974
2017-06-30	78693
2017-09-30	83666
2017-12-31	94464
2018-03-31	99451
2018-06-30	93271
2018-09-30	91741
2018-12-31	95326
2019-03-31	106532
2019-06-30	103633
2019-09-30	103768
2019-12-31	112522
2020-03-31	110013
2020-06-30	108113
2020-09-30	108188
2020-12-31	115348
2021-03-31	109821
2021-06-30	107957
2021-09-30	102996
2021-12-31	103316
2022-03-31	102774
2022-06-30	99133
2022-09-30	92421
2022-12-31	97877
2023-03-31	94209
2023-06-30	93588
2023-09-30	93822