Bi-annual	US dollars
1987-06-30	1303
1987-12-31	1347
1988-06-30	1293
1988-12-31	1323
1989-06-30	815
1989-12-31	1374
1990-06-30	1421
1990-12-31	1601
1991-06-30	848
1991-12-31	794
1992-06-30	818
1992-12-31	809
1993-06-30	1166
1993-12-31	1728
1994-06-30	1554
1994-12-31	2132
1995-06-30	1837
1995-12-31	1861
1996-06-30	1745
1996-12-31	2061
1997-06-30	2256
1997-12-31	2805
1998-06-30	3053
1998-12-31	4049
1999-06-30	3518