Quarter	US dollars
1999-03-31	3812
1999-06-30	3906
1999-09-30	3932
1999-12-31	4171
2000-03-31	3850
2000-06-30	3865
2000-09-30	3580
2000-12-31	3589
2001-03-31	3293
2001-06-30	3250
2001-09-30	3437
2001-12-31	3667
2002-03-31	3321
2002-06-30	3389
2002-09-30	3205
2002-12-31	2992
2003-03-31	3260
2003-06-30	3293
2003-09-30	3275
2003-12-31	3207
2004-03-31	3168
2004-06-30	3131
2004-09-30	3653
2004-12-31	3515
2005-03-31	3481
2005-06-30	3333
2005-09-30	3501
2005-12-31	3081
2006-03-31	3136
2006-06-30	2909
2006-09-30	2614
2006-12-31	2732
2007-03-31	3068
2007-06-30	4544
2007-09-30	7044
2007-12-31	8194
2008-03-31	8937
2008-06-30	9184
2008-09-30	9553
2008-12-31	9134
2009-03-31	8570
2009-06-30	9544
2009-09-30	9485
2009-12-31	8783
2010-03-31	8755
2010-06-30	7494
2010-09-30	6689
2010-12-31	8823
2011-03-31	8335
2011-06-30	8816
2011-09-30	9060
2011-12-31	6967
2012-03-31	6880
2012-06-30	6550
2012-09-30	6565
2012-12-31	5897
2013-03-31	5921
2013-06-30	6049
2013-09-30	6299
2013-12-31	6350
2014-03-31	7440
2014-06-30	7262
2014-09-30	8135
2014-12-31	7627
2015-03-31	7407
2015-06-30	8267
2015-09-30	8622
2015-12-31	10756
2016-03-31	11438
2016-06-30	17361
2016-09-30	19485
2016-12-31	19365
2017-03-31	18424
2017-06-30	18614
2017-09-30	18523
2017-12-31	18994
2018-03-31	20313
2018-06-30	22213
2018-09-30	20439
2018-12-31	20914
2019-03-31	22613
2019-06-30	22307
2019-09-30	21404
2019-12-31	24999
2020-03-31	27197
2020-06-30	27639
2020-09-30	20802
2020-12-31	25196
2021-03-31	22645
2021-06-30	20925
2021-09-30	21707
2021-12-31	21711
2022-03-31	24536
2022-06-30	27784
2022-09-30	24393
2022-12-31	24350
2023-03-31	17727
2023-06-30	21089
2023-09-30	18654