Bi-annual US dollars 1987-06-30 11 1987-12-31 11 1988-06-30 19 1988-12-31 16 1989-06-30 20 1989-12-31 10 1990-06-30 9 1990-12-31 8 1991-06-30 3 1991-12-31 4 1992-06-30 6 1992-12-31 5 1993-06-30 5 1993-12-31 9 1994-06-30 8 1994-12-31 6 1995-06-30 3 1995-12-31 3 1996-06-30 5 1996-12-31 5 1997-06-30 3 1997-12-31 3 1998-06-30 2 1998-12-31 5 1999-06-30 14