Fixed-line traffic, other than international outgoing mobile traffic, international interconnection traffic and international Voice over Internet Protocol traffic, is calculated by dividing traffic operating revenue for the particular category by the weighted average tariff for such category during the relevant period. Fixed-line international outgoing mobile traffic and international interconnection traffic are based on the traffic registered through the respective exchanges and reflected in international interconnection invoices. International Voice over Internet Protocol traffic is based on the traffic reflected in invoices.