Bi-annual	US dollars
1987-06-30	16793
1987-12-31	20965
1988-06-30	17596
1988-12-31	17297
1989-06-30	18331
1989-12-31	20192
1990-06-30	19969
1990-12-31	21996
1991-06-30	19533
1991-12-31	21756
1992-06-30	21746
1992-12-31	22348
1993-06-30	32987
1993-12-31	34158
1994-06-30	38350
1994-12-31	39810
1995-06-30	37456
1995-12-31	39343
1996-06-30	38402
1996-12-31	37483
1997-06-30	44451
1997-12-31	44356
1998-06-30	44032
1998-12-31	37036
1999-06-30	31665