Bi-annual	US dollars
1987-06-30	21145
1987-12-31	21478
1988-06-30	17256
1988-12-31	16646
1989-06-30	17120
1989-12-31	16683
1990-06-30	18500
1990-12-31	19135
1991-06-30	18044
1991-12-31	19795
1992-06-30	20918
1992-12-31	19966
1993-06-30	26392
1993-12-31	28638
1994-06-30	30562
1994-12-31	45098
1995-06-30	50094
1995-12-31	51629
1996-06-30	58408
1996-12-31	72972
1997-06-30	78485
1997-12-31	98173
1998-06-30	104948
1998-12-31	89588
1999-06-30	90236