<prompt> Translate the following text to EnglishKwa njia hii, inadhaniwa kwamba kila mfanyakazi aliingia katika mpango umri wa kuingia wakati wa ajira ya kwanza au tarehe ya mapema ya haki, ikiwa mpango ulikuwapo, na kwamba michango imefanywa kutoka umri wa kuingia hadi tarehe ya tathmini ya akuta.  <response>: The assumption is made under this method that every employee entered the plan entry age at the time of initial employment or at the earliest eligibility date, if the plan had been in existence, and that contributions have been made from the entry age to the date of the actuarial valuation. 