Bi-annual	US dollars
1987-06-30	2588
1987-12-31	2557
1988-06-30	3392
1988-12-31	4538
1989-06-30	3276
1989-12-31	3920
1990-06-30	3553
1990-12-31	4764
1991-06-30	4007
1991-12-31	4475
1992-06-30	3857
1992-12-31	3381
1993-06-30	3279
1993-12-31	2669
1994-06-30	4082
1994-12-31	4110
1995-06-30	3161
1995-12-31	2713
1996-06-30	2470
1996-12-31	2455
1997-06-30	2449
1997-12-31	2282
1998-06-30	4058
1998-12-31	3341
1999-06-30	3255