Quarter	US dollars
1999-03-31	12406
1999-06-30	11803
1999-09-30	10866
1999-12-31	12078
2000-03-31	10838
2000-06-30	11036
2000-09-30	10827
2000-12-31	11422
2001-03-31	11175
2001-06-30	14638
2001-09-30	15449
2001-12-31	18180
2002-03-31	18424
2002-06-30	17097
2002-09-30	17969
2002-12-31	17789
2003-03-31	18663
2003-06-30	15492
2003-09-30	14825
2003-12-31	17060
2004-03-31	17265
2004-06-30	16659
2004-09-30	14132
2004-12-31	13849
2005-03-31	15146
2005-06-30	17473
2005-09-30	14440
2005-12-31	14302
2006-03-31	15550
2006-06-30	14830
2006-09-30	17520
2006-12-31	16708
2007-03-31	22256
2007-06-30	19604
2007-09-30	19983
2007-12-31	24511
2008-03-31	23262
2008-06-30	23763
2008-09-30	24133
2008-12-31	28588
2009-03-31	23574
2009-06-30	26970
2009-09-30	27991
2009-12-31	27550
2010-03-31	32538
2010-06-30	22172
2010-09-30	20037
2010-12-31	28847
2011-03-31	30013
2011-06-30	25607
2011-09-30	25186
2011-12-31	21504
2012-03-31	27712
2012-06-30	23149
2012-09-30	29142
2012-12-31	23250
2013-03-31	22475
2013-06-30	16853
2013-09-30	20132
2013-12-31	19903
2014-03-31	19047
2014-06-30	22041
2014-09-30	20747
2014-12-31	23233
2015-03-31	21549
2015-06-30	26960
2015-09-30	16812
2015-12-31	17548
2016-03-31	15085
2016-06-30	15006
2016-09-30	16604
2016-12-31	17216
2017-03-31	18598
2017-06-30	19716
2017-09-30	20036
2017-12-31	26594
2018-03-31	25475
2018-06-30	27249
2018-09-30	29947
2018-12-31	22780
2019-03-31	26767
2019-06-30	24995
2019-09-30	24686
2019-12-31	24104
2020-03-31	30543
2020-06-30	32410
2020-09-30	30182
2020-12-31	33841
2021-03-31	31798
2021-06-30	45025
2021-09-30	47091
2021-12-31	51769
2022-03-31	46410
2022-06-30	46477
2022-09-30	44782
2022-12-31	49044
2023-03-31	50012
2023-06-30	49278
2023-09-30	51439