Bi-annual	US dollars
1987-06-30	28649
1987-12-31	28831
1988-06-30	31864
1988-12-31	35274
1989-06-30	30855
1989-12-31	35714
1990-06-30	30808
1990-12-31	32443
1991-06-30	34553
1991-12-31	39807
1992-06-30	42922
1992-12-31	35453
1993-06-30	41972
1993-12-31	43033
1994-06-30	49450
1994-12-31	52898
1995-06-30	42627
1995-12-31	45205
1996-06-30	46372
1996-12-31	51158
1997-06-30	49552
1997-12-31	51417
1998-06-30	57975
1998-12-31	63538
1999-06-30	65578