Bi-annual	US dollars
1987-06-30	232
1987-12-31	179
1988-06-30	358
1988-12-31	421
1989-06-30	229
1989-12-31	179
1990-06-30	120
1990-12-31	268
1991-06-30	269
1991-12-31	282
1992-06-30	363
1992-12-31	427
1993-06-30	425
1993-12-31	451
1994-06-30	475
1994-12-31	482
1995-06-30	560
1995-12-31	557
1996-06-30	865
1996-12-31	856
1997-06-30	920
1997-12-31	870
1998-06-30	529
1998-12-31	582
1999-06-30	473