Bi-annual US dollars 1987-06-30 5966 1987-12-31 8091 1988-06-30 6981 1988-12-31 6283 1989-06-30 5641 1989-12-31 5318 1990-06-30 5448 1990-12-31 6010 1991-06-30 5393 1991-12-31 5308 1992-06-30 5741 1992-12-31 5798 1993-06-30 7475 1993-12-31 7726 1994-06-30 9022 1994-12-31 8099 1995-06-30 8638 1995-12-31 7126 1996-06-30 8642 1996-12-31 8122 1997-06-30 14270 1997-12-31 8781 1998-06-30 10151 1998-12-31 8644 1999-06-30 8800