Quarter	US dollars
1999-03-31	19656
1999-06-30	19756
1999-09-30	19043
1999-12-31	20815
2000-03-31	25335
2000-06-30	24099
2000-09-30	28164
2000-12-31	28407
2001-03-31	34446
2001-06-30	35069
2001-09-30	37764
2001-12-31	38172
2002-03-31	42462
2002-06-30	45103
2002-09-30	48262
2002-12-31	48322
2003-03-31	52989
2003-06-30	56201
2003-09-30	59979
2003-12-31	65529
2004-03-31	66330
2004-06-30	62748
2004-09-30	63024
2004-12-31	70414
2005-03-31	79387
2005-06-30	86755
2005-09-30	97489
2005-12-31	96917
2006-03-31	106574
2006-06-30	113641
2006-09-30	92372
2006-12-31	110204
2007-03-31	128146
2007-06-30	143648
2007-09-30	173270
2007-12-31	174195
2008-03-31	194832
2008-06-30	168658
2008-09-30	141799
2008-12-31	157260
2009-03-31	153719
2009-06-30	156835
2009-09-30	163639
2009-12-31	149310
2010-03-31	128836
2010-06-30	151397
2010-09-30	176770
2010-12-31	135819
2011-03-31	145400
2011-06-30	154831
2011-09-30	166549
2011-12-31	152932
2012-03-31	180726
2012-06-30	181167
2012-09-30	187394
2012-12-31	195678
2013-03-31	185705
2013-06-30	171592
2013-09-30	172572
2013-12-31	169156
2014-03-31	177026
2014-06-30	181266
2014-09-30	181584
2014-12-31	188160
2015-03-31	195867
2015-06-30	162953
2015-09-30	158931
2015-12-31	131934
2016-03-31	151055
2016-06-30	152548
2016-09-30	153690
2016-12-31	118434
2017-03-31	117725
2017-06-30	124361
2017-09-30	125484
2017-12-31	126190
2018-03-31	134005
2018-06-30	119320
2018-09-30	118866
2018-12-31	117834
2019-03-31	125565
2019-06-30	137556
2019-09-30	153138
2019-12-31	137254
2020-03-31	148529
2020-06-30	150599
2020-09-30	137853
2020-12-31	113442
2021-03-31	105439
2021-06-30	96791
2021-09-30	85616
2021-12-31	83856
2022-03-31	83154
2022-06-30	85727
2022-09-30	70528
2022-12-31	69572
2023-03-31	68372
2023-06-30	56758
2023-09-30	60315