Bi-annual US dollars 1987-06-30 27 1987-12-31 42 1988-06-30 85 1988-12-31 83 1989-06-30 57 1989-12-31 74 1990-06-30 73 1990-12-31 83 1991-06-30 123 1991-12-31 170 1992-06-30 228 1992-12-31 265 1993-06-30 549 1993-12-31 517 1994-06-30 844 1994-12-31 1022 1995-06-30 1176 1995-12-31 1239 1996-06-30 1621 1996-12-31 1938 1997-06-30 1941 1997-12-31 2805 1998-06-30 2671 1998-12-31 2666 1999-06-30 2793