Bi-annual	US dollars
1987-06-30	735
1987-12-31	704
1988-06-30	638
1988-12-31	651
1989-06-30	557
1989-12-31	495
1990-06-30	399
1990-12-31	382
1991-06-30	313
1991-12-31	402
1992-06-30	419
1992-12-31	344
1993-06-30	408
1993-12-31	260
1994-06-30	350
1994-12-31	447
1995-06-30	649
1995-12-31	743
1996-06-30	917
1996-12-31	1329
1997-06-30	1303
1997-12-31	1280
1998-06-30	1160
1998-12-31	1108
1999-06-30	804