Bi-annual	US dollars
1987-06-30	2490
1987-12-31	2919
1988-06-30	2872
1988-12-31	2558
1989-06-30	2942
1989-12-31	2399
1990-06-30	6369
1990-12-31	6612
1991-06-30	4801
1991-12-31	5721
1992-06-30	6927
1992-12-31	7010
1993-06-30	8221
1993-12-31	7325
1994-06-30	8684
1994-12-31	3949
1995-06-30	5064
1995-12-31	6366
1996-06-30	5904
1996-12-31	7024
1997-06-30	10165
1997-12-31	11007
1998-06-30	14879
1998-12-31	16746
1999-06-30	17037