Bi-annual US dollars 1987-06-30 60 1987-12-31 58 1988-06-30 60 1988-12-31 61 1989-06-30 29 1989-12-31 29 1990-06-30 30 1990-12-31 29 1991-06-30 29 1991-12-31 28 1992-06-30 29 1992-12-31 29 1993-06-30 29 1993-12-31 30 1994-06-30 29 1994-12-31 28 1995-06-30 29 1995-12-31 6 1996-06-30 6 1996-12-31 21 1997-06-30 0 1997-12-31 23 1998-06-30 30 1998-12-31 20 1999-06-30 16