Bi-annual	US dollars
1987-06-30	24839
1987-12-31	29932
1988-06-30	28889
1988-12-31	30870
1989-06-30	33742
1989-12-31	31305
1990-06-30	38649
1990-12-31	44214
1991-06-30	34805
1991-12-31	41355
1992-06-30	41811
1992-12-31	43994
1993-06-30	56720
1993-12-31	52376
1994-06-30	61635
1994-12-31	57950
1995-06-30	59324
1995-12-31	62609
1996-06-30	61591
1996-12-31	61902
1997-06-30	78984
1997-12-31	99013
1998-06-30	114355
1998-12-31	134373
1999-06-30	136912