Bi-annual	US dollars
1987-06-30	5803
1987-12-31	4259
1988-06-30	3667
1988-12-31	3815
1989-06-30	2905
1989-12-31	2364
1990-06-30	2163
1990-12-31	1773
1991-06-30	2144
1991-12-31	1905
1992-06-30	1814
1992-12-31	1535
1993-06-30	1792
1993-12-31	2204
1994-06-30	3037
1994-12-31	2899
1995-06-30	1339
1995-12-31	1436
1996-06-30	2273
1996-12-31	3866
1997-06-30	3370
1997-12-31	2545
1998-06-30	3755
1998-12-31	3353
1999-06-30	2442