Bi-annual	US dollars
1987-06-30	350
1987-12-31	453
1988-06-30	379
1988-12-31	409
1989-06-30	276
1989-12-31	293
1990-06-30	467
1990-12-31	434
1991-06-30	404
1991-12-31	351
1992-06-30	426
1992-12-31	523
1993-06-30	1206
1993-12-31	1203
1994-06-30	1483
1994-12-31	2131
1995-06-30	2051
1995-12-31	2614
1996-06-30	3121
1996-12-31	3306
1997-06-30	4101
1997-12-31	3949
1998-06-30	4050
1998-12-31	4070
1999-06-30	4175