Bi-annual	US dollars
1987-06-30	2533
1987-12-31	2793
1988-06-30	2536
1988-12-31	2399
1989-06-30	2829
1989-12-31	2869
1990-06-30	2998
1990-12-31	3521
1991-06-30	3104
1991-12-31	3549
1992-06-30	3934
1992-12-31	4478
1993-06-30	6832
1993-12-31	6304
1994-06-30	6645
1994-12-31	7065
1995-06-30	7319
1995-12-31	8689
1996-06-30	9653
1996-12-31	11412
1997-06-30	13452
1997-12-31	13128
1998-06-30	11786
1998-12-31	11939
1999-06-30	10897