Bi-annual US dollars 1987-06-30 1097 1987-12-31 981 1988-06-30 906 1988-12-31 819 1989-06-30 839 1989-12-31 834 1990-06-30 680 1990-12-31 785 1991-06-30 816 1991-12-31 783 1992-06-30 1030 1992-12-31 976 1993-06-30 1487 1993-12-31 1797 1994-06-30 1912 1994-12-31 1760 1995-06-30 2081 1995-12-31 1851 1996-06-30 1983 1996-12-31 2506 1997-06-30 2411 1997-12-31 2141 1998-06-30 2221 1998-12-31 1489 1999-06-30 2841