Bi-annual US dollars 1987-06-30 479 1987-12-31 509 1988-06-30 517 1988-12-31 513 1989-06-30 513 1989-12-31 390 1990-06-30 408 1990-12-31 15 1991-06-30 28 1991-12-31 62 1992-06-30 93 1992-12-31 79 1993-06-30 243 1993-12-31 103 1994-06-30 59 1994-12-31 38 1995-06-30 21 1995-12-31 25 1996-06-30 16 1996-12-31 79 1997-06-30 53 1997-12-31 77 1998-06-30 167 1998-12-31 151 1999-06-30 55