For each debtor Member State, the total fixed amount for a calendar year shall be the sum of the products obtained by multiplying, in each age group i, the determined monthly fixed amounts per person by the number of months completed by the persons concerned in the creditor Member State in that age group.
The number of months completed by the persons concerned in the creditor Member State shall be the sum of the calendar months in a calendar year during which the persons concerned were, because of their residence in the territory of the creditor Member State, eligible to receive benefits in kind in that territory at the expense of the debtor Member State. Those months shall be determined from an inventory kept for that purpose by the institution of the place of residence, based on documentary evidence of the entitlement of the beneficiaries supplied by the competent institution.