Bi-annual	US dollars
1987-06-30	187
1987-12-31	181
1988-06-30	159
1988-12-31	188
1989-06-30	146
1989-12-31	176
1990-06-30	155
1990-12-31	185
1991-06-30	174
1991-12-31	301
1992-06-30	409
1992-12-31	433
1993-06-30	383
1993-12-31	353
1994-06-30	461
1994-12-31	427
1995-06-30	393
1995-12-31	421
1996-06-30	395
1996-12-31	469
1997-06-30	542
1997-12-31	446
1998-06-30	790
1998-12-31	1063
1999-06-30	1082