Bi-annual	US dollars
1987-06-30	31908
1987-12-31	33677
1988-06-30	31782
1988-12-31	31779
1989-06-30	29809
1989-12-31	24691
1990-06-30	23199
1990-12-31	23625
1991-06-30	22787
1991-12-31	24700
1992-06-30	24680
1992-12-31	25928
1993-06-30	37562
1993-12-31	40748
1994-06-30	30855
1994-12-31	43167
1995-06-30	44224
1995-12-31	42634
1996-06-30	39703
1996-12-31	43043
1997-06-30	50825
1997-12-31	54586
1998-06-30	63077
1998-12-31	61957
1999-06-30	51339
