Bi-annual US dollars 1987-06-30 77 1987-12-31 77 1988-06-30 72 1988-12-31 69 1989-06-30 65 1989-12-31 50 1990-06-30 49 1990-12-31 42 1991-06-30 58 1991-12-31 56 1992-06-30 48 1992-12-31 41 1993-06-30 42 1993-12-31 40 1994-06-30 45 1994-12-31 45 1995-06-30 75 1995-12-31 64 1996-06-30 84 1996-12-31 72 1997-06-30 60 1997-12-31 69 1998-06-30 172 1998-12-31 161 1999-06-30 139