Quarter	US dollars
1999-03-31	13986
1999-06-30	13715
1999-09-30	15793
1999-12-31	13772
2000-03-31	15788
2000-06-30	16843
2000-09-30	16706
2000-12-31	17305
2001-03-31	17701
2001-06-30	17894
2001-09-30	20191
2001-12-31	17084
2002-03-31	12220
2002-06-30	12172
2002-09-30	10736
2002-12-31	12036
2003-03-31	14329
2003-06-30	15307
2003-09-30	17146
2003-12-31	16966
2004-03-31	16364
2004-06-30	15955
2004-09-30	16180
2004-12-31	17027
2005-03-31	20321
2005-06-30	16110
2005-09-30	18198
2005-12-31	18188
2006-03-31	20682
2006-06-30	20036
2006-09-30	23587
2006-12-31	20510
2007-03-31	19403
2007-06-30	24324
2007-09-30	21643
2007-12-31	22072
2008-03-31	21313
2008-06-30	21725
2008-09-30	22973
2008-12-31	14527
2009-03-31	11313
2009-06-30	12617
2009-09-30	13881
2009-12-31	12461
2010-03-31	13714
2010-06-30	16777
2010-09-30	19112
2010-12-31	16264
2011-03-31	14794
2011-06-30	15327
2011-09-30	14191
2011-12-31	13286
2012-03-31	13009
2012-06-30	9381
2012-09-30	9696
2012-12-31	9493
2013-03-31	9341
2013-06-30	16144
2013-09-30	18430
2013-12-31	17748
2014-03-31	16766
2014-06-30	16914
2014-09-30	18520
2014-12-31	21205
2015-03-31	19562
2015-06-30	20566
2015-09-30	18153
2015-12-31	24314
2016-03-31	12678
2016-06-30	14337
2016-09-30	14035
2016-12-31	15038
2017-03-31	16133
2017-06-30	11674
2017-09-30	11745
2017-12-31	10389
2018-03-31	13440
2018-06-30	15238
2018-09-30	16742
2018-12-31	17649
2019-03-31	14624
2019-06-30	13457
2019-09-30	18304
2019-12-31	16243
2020-03-31	19654
2020-06-30	18319
2020-09-30	17183
2020-12-31	23710
2021-03-31	22962
2021-06-30	21246
2021-09-30	21412
2021-12-31	32600
2022-03-31	29642
2022-06-30	15010
2022-09-30	31773
2022-12-31	33196
2023-03-31	38372
2023-06-30	35285
2023-09-30	17848