Bi-annual US dollars 1987-06-30 15 1987-12-31 49 1988-06-30 55 1988-12-31 61 1989-06-30 51 1989-12-31 44 1990-06-30 10 1990-12-31 14 1991-06-30 19 1991-12-31 41 1992-06-30 44 1992-12-31 39 1993-06-30 42 1993-12-31 52 1994-06-30 68 1994-12-31 95 1995-06-30 111 1995-12-31 175 1996-06-30 211 1996-12-31 243 1997-06-30 196 1997-12-31 171 1998-06-30 183 1998-12-31 181 1999-06-30 150