Bi-annual US dollars 1987-06-30 142 1987-12-31 147 1988-06-30 99 1988-12-31 87 1989-06-30 47 1989-12-31 50 1990-06-30 28 1990-12-31 75 1991-06-30 89 1991-12-31 110 1992-06-30 101 1992-12-31 400 1993-06-30 417 1993-12-31 406 1994-06-30 426 1994-12-31 582 1995-06-30 671 1995-12-31 805 1996-06-30 1181 1996-12-31 1489 1997-06-30 1627 1997-12-31 2004 1998-06-30 1884 1998-12-31 2607 1999-06-30 2108