(8)For the purpose of calculating the indicative Union-wide performance target ranges for the environment KPA, consideration should be given to the historical performance achieved in that KPA, the estimated benefits resulting from measures set out in the European Route Network Improvement Plan referred to in Annex I to Commission Implementing Regulation (EU) 2019/123note, in its version published in July 2023note, and the consequences of Russia’s war of aggression against Ukraine on air traffic flows in the airspace. Furthermore, the proposed indicative Union-wide performance target ranges in the environment KPA should take into account the results of a study conducted by the PRB on the interdependencies between the environment and capacity KPAs, which has been used to appraise the impact of expected capacity constraints on the environment KPA in RP4.