Bi-annual	US dollars
1987-06-30	3767
1987-12-31	4589
1988-06-30	5299
1988-12-31	3466
1989-06-30	5606
1989-12-31	3735
1990-06-30	5931
1990-12-31	4934
1991-06-30	4312
1991-12-31	3963
1992-06-30	6177
1992-12-31	6071
1993-06-30	4836
1993-12-31	5600
1994-06-30	6421
1994-12-31	6558
1995-06-30	7837
1995-12-31	7189
1996-06-30	8167
1996-12-31	5333
1997-06-30	6416
1997-12-31	4972
1998-06-30	6831
1998-12-31	4644
1999-06-30	12542