Quarter	US dollars
1999-03-31	1551
1999-06-30	1428
1999-09-30	1531
1999-12-31	1511
2000-03-31	1757
2000-06-30	2079
2000-09-30	2325
2000-12-31	2629
2001-03-31	2901
2001-06-30	3033
2001-09-30	3578
2001-12-31	3035
2002-03-31	2635
2002-06-30	3034
2002-09-30	3287
2002-12-31	2814
2003-03-31	3087
2003-06-30	2773
2003-09-30	3227
2003-12-31	3872
2004-03-31	4025
2004-06-30	4237
2004-09-30	4699
2004-12-31	5517
2005-03-31	6286
2005-06-30	8272
2005-09-30	10522
2005-12-31	11650
2006-03-31	13673
2006-06-30	16152
2006-09-30	17782
2006-12-31	18391
2007-03-31	19851
2007-06-30	21180
2007-09-30	19892
2007-12-31	20396
2008-03-31	22080
2008-06-30	21970
2008-09-30	24543
2008-12-31	16069
2009-03-31	14793
2009-06-30	15790
2009-09-30	16086
2009-12-31	15713
2010-03-31	15076
2010-06-30	18555
2010-09-30	14322
2010-12-31	11926
2011-03-31	15816
2011-06-30	12082
2011-09-30	11623
2011-12-31	12191
2012-03-31	15135
2012-06-30	14073
2012-09-30	14105
2012-12-31	11082
2013-03-31	13175
2013-06-30	11424
2013-09-30	11293
2013-12-31	10904
2014-03-31	12068
2014-06-30	10954
2014-09-30	11846
2014-12-31	11380
2015-03-31	11076
2015-06-30	11279
2015-09-30	12000
2015-12-31	11603
2016-03-31	11772
2016-06-30	13467
2016-09-30	13565
2016-12-31	12243
2017-03-31	11560
2017-06-30	11455
2017-09-30	10812
2017-12-31	10641
2018-03-31	10174
2018-06-30	10158
2018-09-30	10099
2018-12-31	11220
2019-03-31	10401
2019-06-30	9804
2019-09-30	10067
2019-12-31	9904
2020-03-31	9722
2020-06-30	9951
2020-09-30	9564
2020-12-31	9291
2021-03-31	8706
2021-06-30	7860
2021-09-30	8535
2021-12-31	8615
2022-03-31	8222
2022-06-30	8196
2022-09-30	8858
2022-12-31	9014
2023-03-31	8249
2023-06-30	7734
2023-09-30	7555