Bi-annual US dollars 1987-06-30 100 1987-12-31 96 1988-06-30 51 1988-12-31 105 1989-06-30 79 1989-12-31 129 1990-06-30 70 1990-12-31 100 1991-06-30 115 1991-12-31 106 1992-06-30 202 1992-12-31 144 1993-06-30 411 1993-12-31 470 1994-06-30 383 1994-12-31 1710 1995-06-30 1597 1995-12-31 1578 1996-06-30 1133 1996-12-31 801 1997-06-30 729 1997-12-31 836 1998-06-30 1002 1998-12-31 1398 1999-06-30 1266