Bi-annual	US dollars
1987-06-30	5063
1987-12-31	6061
1988-06-30	5725
1988-12-31	6171
1989-06-30	5705
1989-12-31	6074
1990-06-30	7218
1990-12-31	7625
1991-06-30	7618
1991-12-31	8192
1992-06-30	9692
1992-12-31	10210
1993-06-30	16040
1993-12-31	18286
1994-06-30	16176
1994-12-31	16752
1995-06-30	15430
1995-12-31	14422
1996-06-30	17955
1996-12-31	19406
1997-06-30	21065
1997-12-31	23928
1998-06-30	22190
1998-12-31	25730
1999-06-30	24847