Bi-annual	US dollars
1987-06-30	1113
1987-12-31	1325
1988-06-30	1269
1988-12-31	1257
1989-06-30	1412
1989-12-31	1413
1990-06-30	1308
1990-12-31	1331
1991-06-30	981
1991-12-31	1014
1992-06-30	1494
1992-12-31	1874
1993-06-30	1154
1993-12-31	885
1994-06-30	886
1994-12-31	2103
1995-06-30	1193
1995-12-31	1459
1996-06-30	1403
1996-12-31	1616
1997-06-30	2103
1997-12-31	2257
1998-06-30	1954
1998-12-31	1945
1999-06-30	2167