Bi-annual	US dollars
1987-06-30	4817
1987-12-31	5582
1988-06-30	5584
1988-12-31	6498
1989-06-30	6367
1989-12-31	6456
1990-06-30	7016
1990-12-31	7214
1991-06-30	6749
1991-12-31	6903
1992-06-30	7216
1992-12-31	6972
1993-06-30	14072
1993-12-31	15506
1994-06-30	17066
1994-12-31	18339
1995-06-30	19825
1995-12-31	21744
1996-06-30	22923
1996-12-31	23910
1997-06-30	27943
1997-12-31	36894
1998-06-30	38866
1998-12-31	34902
1999-06-30	35596