Bi-annual US dollars 1987-06-30 52 1987-12-31 72 1988-06-30 84 1988-12-31 52 1989-06-30 17 1989-12-31 24 1990-06-30 21 1990-12-31 17 1991-06-30 24 1991-12-31 49 1992-06-30 103 1992-12-31 77 1993-06-30 248 1993-12-31 281 1994-06-30 312 1994-12-31 386 1995-06-30 426 1995-12-31 544 1996-06-30 475 1996-12-31 305 1997-06-30 314 1997-12-31 490 1998-06-30 722 1998-12-31 802 1999-06-30 1099