A/RES/53/20 Page 3 for the period from 1 July 1998 to 30 June 1999, in addition to the amount of 21,053,745 dollars gross (20,580,245 dollars net) already appropriated under the provisions of its resolution 52/245; 9. Decides also, as an ad hoc arrangement, and taking into account the amount of 21,053,745 dollars gross (20,580,245 dollars net) already apportioned in accordance with its resolution 52/245, to apportion the additional amount of 12,315,418 dollars gross (11,920,452 dollars net) for the period from 1 July 1998 to 28 February 1999 among Member States, in accordance with the composition of groups set out in paragraphs 3 and 4 of General Assembly resolution 43/232 of 1 March 1989, as adjusted by the Assembly in its resolutions 44/192 B of 21 December 1989, 45/269 of 27 August 1991, 46/198 A of 20 December 1991, 47/218 A of 23 December 1992, 49/249 A of 20 July 1995, 49/249 B of 14 September 1995, 50/224 of 11 April 1996, 51/218 A to C of 18 December 1996 and 52/230 of 31 March 1998 and its decisions 48/472 A of 23 December 1993 and 50/451 B of 23 December 1995, and taking into account the scale of assessments for the years 1998 and 1999, as set out in its resolution 52/215 A of 22 December 1997; 10. Decides further that, in accordance with the provisions of its resolution 973 (X) of 15 December 1955, there shall be set off against the apportionment among Member States, as provided for in paragraph 9 above, their respective share in the Tax Equalization Fund of the estimated staff assessment income of 394,966 dollars approved for the Force for the period from 1 July 1998 to 28 February 1999; 11. Decides, as an ad hoc arrangement, to apportion, among Member States, the amount of 16,684,582 dollars gross (16,250,348 dollars net) for the period from 1 March to 30 June 1999 at a monthly rate of 4,171,145.50 dollars gross (4,062,587 dollars net), in accordance with the scheme set out in the present resolution and taking into account the scale of assessments for 1999, as set out in resolution 52/215 A, subject to the decision of the Security Council to extend the mandate of the Force beyond 28 February 1999; 12. Decides also that, in accordance with the provisions of its resolution 973 (X), there shall be set off against the apportionment among Member States, as provided for in paragraph 11 above, their respective share in the Tax Equalization Fund of the estimated staff assessment income of 434,234 dollars approved for the Force for the period from 1 March to 30 June 1999; 13. Invites voluntary contributions to the Force in cash and in the form of services and supplies acceptable to the Secretary-General, to be administered, as appropriate, in accordance with the procedure and practices established by the General Assembly; 14. Decides to keep under review during its fifty-third session the agenda item entitled "Financing of the United Nations Preventive Deployment Force". 50th plenary meeting 2 November 1998