Bi-annual US dollars 1987-06-30 55 1987-12-31 51 1988-06-30 48 1988-12-31 42 1989-06-30 40 1989-12-31 23 1990-06-30 21 1990-12-31 44 1991-06-30 37 1991-12-31 45 1992-06-30 38 1992-12-31 29 1993-06-30 0 1993-12-31 0 1994-06-30 0 1994-12-31 0 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