Quarter	US dollars
1999-09-30	20640
1999-12-31	28902
2000-03-31	22053
2000-06-30	27334
2000-09-30	29375
2000-12-31	34514
2001-03-31	29800
2001-06-30	29274
2001-09-30	29237
2001-12-31	25886
2002-03-31	25270
2002-06-30	28527
2002-09-30	27929
2002-12-31	26793
2003-03-31	26608
2003-06-30	25643
2003-09-30	28075
2003-12-31	28127
2004-03-31	27576
2004-06-30	27308
2004-09-30	27274
2004-12-31	30281
2005-03-31	29382
2005-06-30	29010
2005-09-30	28065
2005-12-31	27367
2006-03-31	28123
2006-06-30	27116
2006-09-30	29298
2006-12-31	30765
2007-03-31	29671
2007-06-30	30000
2007-09-30	28744
2007-12-31	33272
2008-03-31	34252
2008-06-30	34269
2008-09-30	27417
2008-12-31	25884
2009-03-31	21016
2009-06-30	22877
2009-09-30	33720
2009-12-31	33432
2010-03-31	36208
2010-06-30	36362
2010-09-30	39655
2010-12-31	40435
2011-03-31	44368
2011-06-30	48616
2011-09-30	48682
2011-12-31	50236
2012-03-31	51075
2012-06-30	53501
2012-09-30	54232
2012-12-31	55866
2013-03-31	55853
2013-06-30	57821
2013-09-30	60326
2013-12-31	63185
2014-03-31	66955
2014-06-30	67333
2014-09-30	65433
2014-12-31	68038
2015-03-31	85259
2015-06-30	85810
2015-09-30	93085
2015-12-31	94653
2016-03-31	99610
2016-06-30	103879
2016-09-30	106665
2016-12-31	99474
2017-03-31	105133
2017-06-30	109439
2017-09-30	109559
2017-12-31	112944
2018-03-31	114751
2018-06-30	112124
2018-09-30	109764
2018-12-31	122320
2019-03-31	113800
2019-06-30	105037
2019-09-30	95565
2019-12-31	111001
2020-03-31	97276
2020-06-30	95678
2020-09-30	87236
2020-12-31	95306
2021-03-31	88224
2021-06-30	85785
2021-09-30	111850
2021-12-31	114525
2022-03-31	113007
2022-06-30	102710
2022-09-30	93149
2022-12-31	103805
2023-03-31	101911
2023-06-30	100781
2023-09-30	100187
2023-12-31	104598