Bi-annual	US dollars
1987-06-30	4405
1987-12-31	4691
1988-06-30	3331
1988-12-31	3061
1989-06-30	2612
1989-12-31	2691
1990-06-30	3085
1990-12-31	3564
1991-06-30	3574
1991-12-31	5187
1992-06-30	5298
1992-12-31	8601
1993-06-30	19922
1993-12-31	23655
1994-06-30	14202
1994-12-31	26397
1995-06-30	28213
1995-12-31	26707
1996-06-30	25203
1996-12-31	27255
1997-06-30	34171
1997-12-31	37393
1998-06-30	44380
1998-12-31	42928
1999-06-30	33830