Bi-annual	US dollars
1987-06-30	4387
1987-12-31	5335
1988-06-30	6578
1988-12-31	7952
1989-06-30	6954
1989-12-31	7084
1990-06-30	6921
1990-12-31	6746
1991-06-30	7162
1991-12-31	8247
1992-06-30	8392
1992-12-31	8284
1993-06-30	11008
1993-12-31	11613
1994-06-30	14690
1994-12-31	14406
1995-06-30	14987
1995-12-31	18997
1996-06-30	17916
1996-12-31	16177
1997-06-30	19052
1997-12-31	19313
1998-06-30	17693
1998-12-31	21516
1999-06-30	18117