Bi-annual	US dollars
1987-06-30	36721
1987-12-31	43939
1988-06-30	42445
1988-12-31	41148
1989-06-30	42644
1989-12-31	47254
1990-06-30	47965
1990-12-31	54846
1991-06-30	47936
1991-12-31	53072
1992-06-30	56995
1992-12-31	56050
1993-06-30	71940
1993-12-31	74303
1994-06-30	74862
1994-12-31	91939
1995-06-30	93036
1995-12-31	84805
1996-06-30	94354
1996-12-31	95320
1997-06-30	105921
1997-12-31	109626
1998-06-30	129302
1998-12-31	126065
1999-06-30	138367