Bi-annual	US dollars
1987-06-30	17178
1987-12-31	18215
1988-06-30	18274
1988-12-31	16299
1989-06-30	15966
1989-12-31	16354
1990-06-30	15747
1990-12-31	16158
1991-06-30	13120
1991-12-31	14567
1992-06-30	13207
1992-12-31	13031
1993-06-30	33835
1993-12-31	31570
1994-06-30	33548
1994-12-31	31752
1995-06-30	35212
1995-12-31	41389
1996-06-30	42724
1996-12-31	45652
1997-06-30	50036
1997-12-31	53502
1998-06-30	49114
1998-12-31	42256
1999-06-30	39090