Bi-annual	US dollars
1987-06-30	7140
1987-12-31	7801
1988-06-30	7313
1988-12-31	7650
1989-06-30	7514
1989-12-31	9269
1990-06-30	8615
1990-12-31	10890
1991-06-30	11916
1991-12-31	12720
1992-06-30	14177
1992-12-31	13161
1993-06-30	14523
1993-12-31	12680
1994-06-30	14228
1994-12-31	15511
1995-06-30	15484
1995-12-31	14396
1996-06-30	14338
1996-12-31	20607
1997-06-30	11950
1997-12-31	20188
1998-06-30	24351
1998-12-31	24121
1999-06-30	24883