Bi-annual US dollars 1987-06-30 6 1987-12-31 6 1988-06-30 9 1988-12-31 9 1989-06-30 8 1989-12-31 10 1990-06-30 14 1990-12-31 10 1991-06-30 10 1991-12-31 11 1992-06-30 4 1992-12-31 6 1993-06-30 8 1993-12-31 18 1994-06-30 3 1994-12-31 6 1995-06-30 5 1995-12-31 6 1996-06-30 19 1996-12-31 14 1997-06-30 62 1997-12-31 56 1998-06-30 53 1998-12-31 50 1999-06-30 46