Bi-annual	US dollars
1987-06-30	597
1987-12-31	536
1988-06-30	462
1988-12-31	459
1989-06-30	383
1989-12-31	313
1990-06-30	136
1990-12-31	133
1991-06-30	135
1991-12-31	129
1992-06-30	152
1992-12-31	82
1993-06-30	239
1993-12-31	251
1994-06-30	301
1994-12-31	319
1995-06-30	383
1995-12-31	305
1996-06-30	365
1996-12-31	452
1997-06-30	469
1997-12-31	451
1998-06-30	502
1998-12-31	547
1999-06-30	620