Bi-annual	US dollars
1987-06-30	866
1987-12-31	489
1988-06-30	512
1988-12-31	609
1989-06-30	518
1989-12-31	642
1990-06-30	598
1990-12-31	561
1991-06-30	511
1991-12-31	814
1992-06-30	797
1992-12-31	938
1993-06-30	1013
1993-12-31	897
1994-06-30	949
1994-12-31	934
1995-06-30	834
1995-12-31	837
1996-06-30	738
1996-12-31	789
1997-06-30	719
1997-12-31	663
1998-06-30	592
1998-12-31	709
1999-06-30	828