Quarter	US dollars
1999-03-31	4935
1999-06-30	5200
1999-09-30	5343
1999-12-31	4731
2000-03-31	4536
2000-06-30	5367
2000-09-30	6604
2000-12-31	6974
2001-03-31	6266
2001-06-30	6312
2001-09-30	7455
2001-12-31	6129
2002-03-31	5976
2002-06-30	5616
2002-09-30	5114
2002-12-31	5553
2003-03-31	6003
2003-06-30	5420
2003-09-30	4757
2003-12-31	5976
2004-03-31	8412
2004-06-30	7153
2004-09-30	7851
2004-12-31	8551
2005-03-31	7802
2005-06-30	10101
2005-09-30	8931
2005-12-31	11282
2006-03-31	17653
2006-06-30	13225
2006-09-30	13477
2006-12-31	14733
2007-03-31	13784
2007-06-30	13212
2007-09-30	16793
2007-12-31	15817
2008-03-31	19375
2008-06-30	17993
2008-09-30	18721
2008-12-31	22556
2009-03-31	17918
2009-06-30	21826
2009-09-30	23430
2009-12-31	21515
2010-03-31	21808
2010-06-30	14263
2010-09-30	14351
2010-12-31	10746
2011-03-31	17291
2011-06-30	18463
2011-09-30	16471
2011-12-31	15885
2012-03-31	18422
2012-06-30	22709
2012-09-30	19483
2012-12-31	14193
2013-03-31	12883
2013-06-30	12812
2013-09-30	10641
2013-12-31	9797
2014-03-31	8132
2014-06-30	7278
2014-09-30	7815
2014-12-31	8170
2015-03-31	8416
2015-06-30	9444
2015-09-30	9503
2015-12-31	8500
2016-03-31	9140
2016-06-30	7541
2016-09-30	6726
2016-12-31	5945
2017-03-31	6040
2017-06-30	5745
2017-09-30	5515
2017-12-31	7409
2018-03-31	8516
2018-06-30	11911
2018-09-30	7274
2018-12-31	6514
2019-03-31	5942
2019-06-30	7361
2019-09-30	5961
2019-12-31	5053
2020-03-31	5710
2020-06-30	6700
2020-09-30	7095
2020-12-31	6372
2021-03-31	4657
2021-06-30	4161
2021-09-30	5024
2021-12-31	5710
2022-03-31	5627
2022-06-30	5512
2022-09-30	5729
2022-12-31	5114
2023-03-31	5272
2023-06-30	5159
2023-09-30	5508