Bi-annual US dollars 1987-06-30 39 1987-12-31 49 1988-06-30 36 1988-12-31 224 1989-06-30 25 1989-12-31 16 1990-06-30 23 1990-12-31 17 1991-06-30 19 1991-12-31 69 1992-06-30 57 1992-12-31 59 1993-06-30 42 1993-12-31 50 1994-06-30 105 1994-12-31 152 1995-06-30 240 1995-12-31 91 1996-06-30 76 1996-12-31 91 1997-06-30 131 1997-12-31 280 1998-06-30 390 1998-12-31 586 1999-06-30 541