Bi-annual US dollars 1987-06-30 48 1987-12-31 183 1988-06-30 53 1988-12-31 76 1989-06-30 39 1989-12-31 158 1990-06-30 51 1990-12-31 48 1991-06-30 349 1991-12-31 26 1992-06-30 1673 1992-12-31 2139 1993-06-30 165 1993-12-31 55 1994-06-30 96 1994-12-31 55 1995-06-30 24 1995-12-31 85 1996-06-30 65 1996-12-31 79 1997-06-30 108 1997-12-31 314 1998-06-30 417 1998-12-31 53 1999-06-30 25