Bi-annual	US dollars
1987-06-30	1221
1987-12-31	1176
1988-06-30	1030
1988-12-31	976
1989-06-30	896
1989-12-31	405
1990-06-30	452
1990-12-31	479
1991-06-30	433
1991-12-31	581
1992-06-30	624
1992-12-31	483
1993-06-30	632
1993-12-31	599
1994-06-30	579
1994-12-31	749
1995-06-30	550
1995-12-31	710
1996-06-30	402
1996-12-31	461
1997-06-30	389
1997-12-31	459
1998-06-30	575
1998-12-31	900
1999-06-30	844