Bi-annual US dollars 1987-06-30 568 1987-12-31 445 1988-06-30 450 1988-12-31 293 1989-06-30 341 1989-12-31 440 1990-06-30 194 1990-12-31 81 1991-06-30 159 1991-12-31 164 1992-06-30 474 1992-12-31 489 1993-06-30 854 1993-12-31 1725 1994-06-30 1957 1994-12-31 2004 1995-06-30 1586 1995-12-31 1316 1996-06-30 1695 1996-12-31 2101 1997-06-30 1938 1997-12-31 2920 1998-06-30 2646 1998-12-31 2486 1999-06-30 3217