Quarter	US dollars
1999-03-31	8342
1999-06-30	8675
1999-09-30	9506
1999-12-31	8310
2000-03-31	9486
2000-06-30	8400
2000-09-30	9669
2000-12-31	9683
2001-03-31	11295
2001-06-30	9006
2001-09-30	10333
2001-12-31	11471
2002-03-31	11381
2002-06-30	11608
2002-09-30	12513
2002-12-31	14788
2003-03-31	16129
2003-06-30	20102
2003-09-30	19903
2003-12-31	20407
2004-03-31	20919
2004-06-30	21676
2004-09-30	25916
2004-12-31	29153
2005-03-31	29738
2005-06-30	28040
2005-09-30	33625
2005-12-31	33979
2006-03-31	37246
2006-06-30	46000
2006-09-30	48307
2006-12-31	60444
2007-03-31	66014
2007-06-30	73149
2007-09-30	75950
2007-12-31	71862
2008-03-31	75215
2008-06-30	80688
2008-09-30	73784
2008-12-31	62930
2009-03-31	64491
2009-06-30	68167
2009-09-30	61156
2009-12-31	55411
2010-03-31	49865
2010-06-30	45439
2010-09-30	51171
2010-12-31	49345
2011-03-31	47719
2011-06-30	50432
2011-09-30	46552
2011-12-31	44495
2012-03-31	41755
2012-06-30	36783
2012-09-30	35674
2012-12-31	36227
2013-03-31	31769
2013-06-30	29504
2013-09-30	28138
2013-12-31	32134
2014-03-31	28143
2014-06-30	30562
2014-09-30	25568
2014-12-31	29436
2015-03-31	25184
2015-06-30	25748
2015-09-30	24231
2015-12-31	19410
2016-03-31	25282
2016-06-30	21426
2016-09-30	20072
2016-12-31	19050
2017-03-31	18475
2017-06-30	19183
2017-09-30	19733
2017-12-31	21244
2018-03-31	25373
2018-06-30	21835
2018-09-30	23773
2018-12-31	25125
2019-03-31	28566
2019-06-30	26067
2019-09-30	28288
2019-12-31	23662
2020-03-31	26810
2020-06-30	23819
2020-09-30	26267
2020-12-31	24090
2021-03-31	22972
2021-06-30	25698
2021-09-30	18653
2021-12-31	14920
2022-03-31	13610
2022-06-30	13337
2022-09-30	11870
2022-12-31	13530
2023-03-31	14840
2023-06-30	15081
2023-09-30	14807