Bi-annual US dollars 1987-06-30 0 1987-12-31 0 1988-06-30 0 1988-12-31 0 1989-06-30 0 1989-12-31 0 1990-06-30 0 1990-12-31 0 1991-06-30 0 1991-12-31 0 1992-06-30 0 1992-12-31 0 1993-06-30 0 1993-12-31 80 1994-06-30 26 1994-12-31 33 1995-06-30 54 1995-12-31 79 1996-06-30 123 1996-12-31 147 1997-06-30 135 1997-12-31 151 1998-06-30 0 1998-12-31 0 1999-06-30 0