Bi-annual	US dollars
1987-06-30	5154
1987-12-31	6540
1988-06-30	4683
1988-12-31	5137
1989-06-30	5069
1989-12-31	5394
1990-06-30	6439
1990-12-31	6643
1991-06-30	4892
1991-12-31	6823
1992-06-30	7024
1992-12-31	7528
1993-06-30	10031
1993-12-31	9461
1994-06-30	9775
1994-12-31	10583
1995-06-30	8169
1995-12-31	8874
1996-06-30	7200
1996-12-31	8522
1997-06-30	8365
1997-12-31	13473
1998-06-30	15874
1998-12-31	13355
1999-06-30	17162