Bi-annual US dollars 1987-06-30 11 1987-12-31 30 1988-06-30 36 1988-12-31 14 1989-06-30 19 1989-12-31 119 1990-06-30 37 1990-12-31 6 1991-06-30 10 1991-12-31 17 1992-06-30 10 1992-12-31 26 1993-06-30 45 1993-12-31 24 1994-06-30 34 1994-12-31 47 1995-06-30 35 1995-12-31 43 1996-06-30 47 1996-12-31 171 1997-06-30 40 1997-12-31 38 1998-06-30 43 1998-12-31 43 1999-06-30 30