(f) the society shall operate on an insurance basis, that is to say,--
(i) it shall levy its premiums in respect of a period not exceeding twelve months, during which period the insured shall be held covered in respect of all accidents arising, subject to the limits of liability specified in 5[ sub- section (2) of section 95;
(ii) it shall charge premiums estimated to be sufficient, having regard to the risks, to meet the capitalised value of all claims arising during the period of cover, together with an adequate charge for expenses attaching to the issue of policies and to the settlement of claims arising thereunder;