Bi-annual US dollars 1987-06-30 90 1987-12-31 119 1988-06-30 58 1988-12-31 130 1989-06-30 84 1989-12-31 37 1990-06-30 26 1990-12-31 19 1991-06-30 8 1991-12-31 9 1992-06-30 10 1992-12-31 12 1993-06-30 14 1993-12-31 15 1994-06-30 56 1994-12-31 19 1995-06-30 113 1995-12-31 118 1996-06-30 112 1996-12-31 115 1997-06-30 101 1997-12-31 51 1998-06-30 67 1998-12-31 52 1999-06-30 44