Bi-annual	US dollars
1987-06-30	12216
1987-12-31	12467
1988-06-30	13074
1988-12-31	14406
1989-06-30	9369
1989-12-31	12442
1990-06-30	10539
1990-12-31	9632
1991-06-30	13411
1991-12-31	15817
1992-06-30	17098
1992-12-31	15542
1993-06-30	16504
1993-12-31	16635
1994-06-30	20264
1994-12-31	21429
1995-06-30	19350
1995-12-31	9342
1996-06-30	10310
1996-12-31	11939
1997-06-30	12911
1997-12-31	13695
1998-06-30	11801
1998-12-31	14785
1999-06-30	13474