Bi-annual US dollars 1987-06-30 27027 1987-12-31 33738 1988-06-30 31809 1988-12-31 31879 1989-06-30 31410 1989-12-31 37242 1990-06-30 36453 1990-12-31 42140 1991-06-30 35744 1991-12-31 39388 1992-06-30 40561 1992-12-31 38243 1993-06-30 48465 1993-12-31 47487 1994-06-30 51784 1994-12-31 54837 1995-06-30 55782 1995-12-31 45280 1996-06-30 53878 1996-12-31 51501 1997-06-30 51686 1997-12-31 63675 1998-06-30 66854 1998-12-31 69452 1999-06-30 74573