Bi-annual US dollars 1987-06-30 24 1987-12-31 25 1988-06-30 31 1988-12-31 33 1989-06-30 28 1989-12-31 27 1990-06-30 21 1990-12-31 23 1991-06-30 21 1991-12-31 21 1992-06-30 27 1992-12-31 35 1993-06-30 23 1993-12-31 4 1994-06-30 5 1994-12-31 3 1995-06-30 3 1995-12-31 6 1996-06-30 28 1996-12-31 31 1997-06-30 7 1997-12-31 13 1998-06-30 15 1998-12-31 12 1999-06-30 13