Quarter	US dollars
1999-03-31	12774
1999-06-30	12108
1999-09-30	12896
1999-12-31	11370
2000-03-31	13098
2000-06-30	13354
2000-09-30	13392
2000-12-31	11394
2001-03-31	13816
2001-06-30	12668
2001-09-30	13029
2001-12-31	11071
2002-03-31	12045
2002-06-30	12214
2002-09-30	13189
2002-12-31	13318
2003-03-31	15137
2003-06-30	16184
2003-09-30	13661
2003-12-31	14895
2004-03-31	17337
2004-06-30	17066
2004-09-30	14926
2004-12-31	15264
2005-03-31	17476
2005-06-30	16806
2005-09-30	18767
2005-12-31	15273
2006-03-31	16563
2006-06-30	17029
2006-09-30	16305
2006-12-31	17779
2007-03-31	16745
2007-06-30	17930
2007-09-30	20237
2007-12-31	18524
2008-03-31	15464
2008-06-30	14918
2008-09-30	12118
2008-12-31	14123
2009-03-31	15231
2009-06-30	13795
2009-09-30	12848
2009-12-31	10385
2010-03-31	11168
2010-06-30	12812
2010-09-30	13646
2010-12-31	10770
2011-03-31	12250
2011-06-30	9668
2011-09-30	13964
2011-12-31	12091
2012-03-31	10427
2012-06-30	9594
2012-09-30	10236
2012-12-31	7910
2013-03-31	8782
2013-06-30	8050
2013-09-30	8016
2013-12-31	6821
2014-03-31	9892
2014-06-30	10280
2014-09-30	9115
2014-12-31	8033
2015-03-31	8597
2015-06-30	8408
2015-09-30	10099
2015-12-31	9108
2016-03-31	8005
2016-06-30	10263
2016-09-30	9926
2016-12-31	6883
2017-03-31	8061
2017-06-30	7739
2017-09-30	6592
2017-12-31	6391
2018-03-31	8705
2018-06-30	6798
2018-09-30	6073
2018-12-31	4956
2019-03-31	5017
2019-06-30	5195
2019-09-30	5304
2019-12-31	4727
2020-03-31	4291
2020-06-30	4145
2020-09-30	5355
2020-12-31	5072
2021-03-31	5966
2021-06-30	5735
2021-09-30	5538
2021-12-31	4381
2022-03-31	4192
2022-06-30	4402
2022-09-30	4694
2022-12-31	3529
2023-03-31	3833
2023-06-30	3127
2023-09-30	3429