Bi-annual US dollars 1987-06-30 21 1987-12-31 51 1988-06-30 53 1988-12-31 52 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 30 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 0 1996-06-30 0 1996-12-31 0 1997-06-30 7 1997-12-31 2 1998-06-30 2 1998-12-31 2 1999-06-30 5