Bi-annual US dollars 1987-06-30 79 1987-12-31 89 1988-06-30 82 1988-12-31 85 1989-06-30 88 1989-12-31 81 1990-06-30 54 1990-12-31 54 1991-06-30 54 1991-12-31 56 1992-06-30 55 1992-12-31 55 1993-06-30 41 1993-12-31 58 1994-06-30 59 1994-12-31 89 1995-06-30 6 1995-12-31 9 1996-06-30 12 1996-12-31 10 1997-06-30 3 1997-12-31 3 1998-06-30 2 1998-12-31 2 1999-06-30 2