Bi-annual	US dollars
1987-06-30	1851
1987-12-31	2302
1988-06-30	2239
1988-12-31	2186
1989-06-30	1777
1989-12-31	1782
1990-06-30	1753
1990-12-31	1395
1991-06-30	1145
1991-12-31	2645
1992-06-30	2508
1992-12-31	903
1993-06-30	806
1993-12-31	1024
1994-06-30	1153
1994-12-31	1740
1995-06-30	2213
1995-12-31	1692
1996-06-30	1742
1996-12-31	1618
1997-06-30	1580
1997-12-31	1517
1998-06-30	2951
1998-12-31	1819
1999-06-30	1839