Quarter	US dollars
1999-03-31	10760
1999-06-30	11690
1999-09-30	13489
1999-12-31	12504
2000-03-31	13689
2000-06-30	12696
2000-09-30	9708
2000-12-31	10330
2001-03-31	11198
2001-06-30	9513
2001-09-30	10485
2001-12-31	9517
2002-03-31	10031
2002-06-30	10293
2002-09-30	7895
2002-12-31	6973
2003-03-31	9490
2003-06-30	11647
2003-09-30	11508
2003-12-31	11950
2004-03-31	17215
2004-06-30	15478
2004-09-30	21527
2004-12-31	19151
2005-03-31	18590
2005-06-30	14915
2005-09-30	13301
2005-12-31	15161
2006-03-31	19628
2006-06-30	20786
2006-09-30	22860
2006-12-31	18824
2007-03-31	22716
2007-06-30	23259
2007-09-30	32714
2007-12-31	29470
2008-03-31	28856
2008-06-30	20392
2008-09-30	18654
2008-12-31	13374
2009-03-31	15620
2009-06-30	13437
2009-09-30	14167
2009-12-31	11747
2010-03-31	15444
2010-06-30	13244
2010-09-30	15910
2010-12-31	12256
2011-03-31	15606
2011-06-30	15247
2011-09-30	14996
2011-12-31	14246
2012-03-31	13361
2012-06-30	13228
2012-09-30	15714
2012-12-31	17847
2013-03-31	15951
2013-06-30	16999
2013-09-30	17723
2013-12-31	17766
2014-03-31	19011
2014-06-30	17640
2014-09-30	16958
2014-12-31	18479
2015-03-31	16658
2015-06-30	15517
2015-09-30	14138
2015-12-31	17969
2016-03-31	17266
2016-06-30	18827
2016-09-30	21556
2016-12-31	18355
2017-03-31	18485
2017-06-30	20968
2017-09-30	21516
2017-12-31	20995
2018-03-31	21622
2018-06-30	21975
2018-09-30	20470
2018-12-31	16311
2019-03-31	18261
2019-06-30	15184
2019-09-30	15323
2019-12-31	16097
2020-03-31	16772
2020-06-30	13817
2020-09-30	14491
2020-12-31	15302
2021-03-31	13571
2021-06-30	13830
2021-09-30	13419
2021-12-31	14123
2022-03-31	11664
2022-06-30	11541
2022-09-30	11407
2022-12-31	9819
2023-03-31	11224
2023-06-30	11196
2023-09-30	13673