Bi-annual	US dollars
1987-06-30	21688
1987-12-31	19504
1988-06-30	19289
1988-12-31	20161
1989-06-30	20163
1989-12-31	22130
1990-06-30	22090
1990-12-31	24051
1991-06-30	23757
1991-12-31	25682
1992-06-30	27142
1992-12-31	23676
1993-06-30	29692
1993-12-31	28503
1994-06-30	31301
1994-12-31	43972
1995-06-30	48836
1995-12-31	48065
1996-06-30	59346
1996-12-31	72086
1997-06-30	63786
1997-12-31	82499
1998-06-30	98322
1998-12-31	84671
1999-06-30	85847