Bi-annual	US dollars
1987-06-30	1406
1987-12-31	1615
1988-06-30	1562
1988-12-31	1658
1989-06-30	1268
1989-12-31	943
1990-06-30	947
1990-12-31	1208
1991-06-30	1255
1991-12-31	1251
1992-06-30	2672
1992-12-31	2454
1993-06-30	3576
1993-12-31	4410
1994-06-30	4497
1994-12-31	4678
1995-06-30	5351
1995-12-31	4482
1996-06-30	5680
1996-12-31	5701
1997-06-30	5175
1997-12-31	5518
1998-06-30	9122
1998-12-31	6951
1999-06-30	8786