Bi-annual	US dollars
1987-06-30	3191
1987-12-31	3817
1988-06-30	4752
1988-12-31	6364
1989-06-30	5418
1989-12-31	5523
1990-06-30	4477
1990-12-31	4278
1991-06-30	4428
1991-12-31	5303
1992-06-30	5045
1992-12-31	4430
1993-06-30	6692
1993-12-31	7142
1994-06-30	7515
1994-12-31	6001
1995-06-30	6481
1995-12-31	8563
1996-06-30	7559
1996-12-31	8690
1997-06-30	10434
1997-12-31	9495
1998-06-30	9147
1998-12-31	10365
1999-06-30	11594