Bi-annual US dollars 1987-06-30 26 1987-12-31 25 1988-06-30 15 1988-12-31 31 1989-06-30 17 1989-12-31 31 1990-06-30 19 1990-12-31 15 1991-06-30 21 1991-12-31 7 1992-06-30 8 1992-12-31 8 1993-06-30 6 1993-12-31 1 1994-06-30 2 1994-12-31 3 1995-06-30 32 1995-12-31 33 1996-06-30 26 1996-12-31 31 1997-06-30 67 1997-12-31 67 1998-06-30 72 1998-12-31 67 1999-06-30 16