Bi-annual US dollars 1987-06-30 48 1987-12-31 23 1988-06-30 48 1988-12-31 40 1989-06-30 37 1989-12-31 10 1990-06-30 24 1990-12-31 10 1991-06-30 8 1991-12-31 17 1992-06-30 23 1992-12-31 20 1993-06-30 20 1993-12-31 19 1994-06-30 40 1994-12-31 23 1995-06-30 17 1995-12-31 20 1996-06-30 30 1996-12-31 27 1997-06-30 32 1997-12-31 28 1998-06-30 30 1998-12-31 20 1999-06-30 20