Bi-annual US dollars 1987-06-30 5 1987-12-31 30 1988-06-30 5 1988-12-31 4 1989-06-30 5 1989-12-31 3 1990-06-30 3 1990-12-31 4 1991-06-30 3 1991-12-31 6 1992-06-30 6 1992-12-31 8 1993-06-30 17 1993-12-31 22 1994-06-30 17 1994-12-31 30 1995-06-30 25 1995-12-31 26 1996-06-30 20 1996-12-31 38 1997-06-30 37 1997-12-31 74 1998-06-30 37 1998-12-31 68 1999-06-30 32