Bi-annual US dollars 1987-06-30 337 1987-12-31 409 1988-06-30 321 1988-12-31 334 1989-06-30 319 1989-12-31 300 1990-06-30 251 1990-12-31 226 1991-06-30 174 1991-12-31 164 1992-06-30 156 1992-12-31 121 1993-06-30 120 1993-12-31 67 1994-06-30 43 1994-12-31 47 1995-06-30 46 1995-12-31 51 1996-06-30 75 1996-12-31 135 1997-06-30 213 1997-12-31 485 1998-06-30 505 1998-12-31 310 1999-06-30 473