Bi-annual US dollars 1987-06-30 108 1987-12-31 177 1988-06-30 119 1988-12-31 56 1989-06-30 110 1989-12-31 32 1990-06-30 28 1990-12-31 46 1991-06-30 63 1991-12-31 62 1992-06-30 95 1992-12-31 183 1993-06-30 158 1993-12-31 273 1994-06-30 273 1994-12-31 1594 1995-06-30 1366 1995-12-31 740 1996-06-30 186 1996-12-31 231 1997-06-30 226 1997-12-31 745 1998-06-30 947 1998-12-31 611 1999-06-30 451