Bi-annual US dollars 1987-06-30 79 1987-12-31 81 1988-06-30 67 1988-12-31 63 1989-06-30 56 1989-12-31 56 1990-06-30 51 1990-12-31 48 1991-06-30 42 1991-12-31 39 1992-06-30 29 1992-12-31 24 1993-06-30 12 1993-12-31 13 1994-06-30 5 1994-12-31 2 1995-06-30 0 1995-12-31 0 1996-06-30 0 1996-12-31 0 1997-06-30 0 1997-12-31 0 1998-06-30 0 1998-12-31 0 1999-06-30 0