Bi-annual US dollars 1987-06-30 39 1987-12-31 30 1988-06-30 67 1988-12-31 199 1989-06-30 50 1989-12-31 39 1990-06-30 44 1990-12-31 44 1991-06-30 50 1991-12-31 90 1992-06-30 120 1992-12-31 118 1993-06-30 179 1993-12-31 207 1994-06-30 309 1994-12-31 447 1995-06-30 590 1995-12-31 620 1996-06-30 611 1996-12-31 817 1997-06-30 933 1997-12-31 1372 1998-06-30 1177 1998-12-31 1233 1999-06-30 1126