Bi-annual	US dollars
1987-06-30	2633
1987-12-31	2742
1988-06-30	2277
1988-12-31	3010
1989-06-30	2789
1989-12-31	3572
1990-06-30	3031
1990-12-31	4309
1991-06-30	4665
1991-12-31	5445
1992-06-30	5562
1992-12-31	5727
1993-06-30	5505
1993-12-31	7428
1994-06-30	5410
1994-12-31	8063
1995-06-30	6834
1995-12-31	6105
1996-06-30	5669
1996-12-31	6755
1997-06-30	7126
1997-12-31	7871
1998-06-30	9940
1998-12-31	11879
1999-06-30	11928