Bi-annual	US dollars
1987-06-30	10181
1987-12-31	9482
1988-06-30	11045
1988-12-31	11996
1989-06-30	8321
1989-12-31	11350
1990-06-30	8380
1990-12-31	8993
1991-06-30	13120
1991-12-31	15266
1992-06-30	16343
1992-12-31	15012
1993-06-30	15680
1993-12-31	16054
1994-06-30	19342
1994-12-31	20473
1995-06-30	7157
1995-12-31	8495
1996-06-30	9074
1996-12-31	10657
1997-06-30	11670
1997-12-31	11514
1998-06-30	10507
1998-12-31	13620
1999-06-30	12493