Bi-annual	US dollars
1987-06-30	956
1987-12-31	1004
1988-06-30	894
1988-12-31	1103
1989-06-30	750
1989-12-31	850
1990-06-30	717
1990-12-31	778
1991-06-30	598
1991-12-31	629
1992-06-30	679
1992-12-31	573
1993-06-30	630
1993-12-31	452
1994-06-30	614
1994-12-31	666
1995-06-30	818
1995-12-31	727
1996-06-30	822
1996-12-31	993
1997-06-30	1056
1997-12-31	1186
1998-06-30	1219
1998-12-31	1616
1999-06-30	1641