Bi-annual US dollars 1987-06-30 47 1987-12-31 42 1988-06-30 29 1988-12-31 27 1989-06-30 31 1989-12-31 42 1990-06-30 23 1990-12-31 15 1991-06-30 31 1991-12-31 30 1992-06-30 34 1992-12-31 23 1993-06-30 41 1993-12-31 28 1994-06-30 113 1994-12-31 39 1995-06-30 84 1995-12-31 112 1996-06-30 190 1996-12-31 281 1997-06-30 454 1997-12-31 191 1998-06-30 153 1998-12-31 42 1999-06-30 319