Bi-annual	US dollars
1987-06-30	3983
1987-12-31	3665
1988-06-30	2944
1988-12-31	2987
1989-06-30	2531
1989-12-31	2425
1990-06-30	2272
1990-12-31	2209
1991-06-30	2148
1991-12-31	2404
1992-06-30	2619
1992-12-31	2521
1993-06-30	2797
1993-12-31	2564
1994-06-30	2526
1994-12-31	2511
1995-06-30	2343
1995-12-31	2746
1996-06-30	3224
1996-12-31	3527
1997-06-30	3983
1997-12-31	3343
1998-06-30	3463
1998-12-31	3890
1999-06-30	3901