Bi-annual	US dollars
1987-06-30	1051
1987-12-31	1251
1988-06-30	1734
1988-12-31	1343
1989-06-30	2046
1989-12-31	2435
1990-06-30	2668
1990-12-31	3153
1991-06-30	2350
1991-12-31	2854
1992-06-30	3262
1992-12-31	1841
1993-06-30	1682
1993-12-31	1271
1994-06-30	1049
1994-12-31	3360
1995-06-30	2394
1995-12-31	1975
1996-06-30	2590
1996-12-31	1832
1997-06-30	1421
1997-12-31	1502
1998-06-30	2179
1998-12-31	2792
1999-06-30	3136