Joined Cases T-230/01 to T-232/01 and T-267/01 to T-269/01: Judgment of the Court of First Instance of 9 September 2009 — Diputación Foral de Álava and Others v Commission (State aid — Tax advantages granted by a territorial entity within a Member State — Reduction of the tax base for corporation tax — Decisions declaring aid schemes incompatible with the common market and requiring recovery of aid paid out — Trade association — Admissibility — Withdrawal of a plea in law — Classification as new aid or as existing aid — Principle of the protection of legitimate expectations — Principle of legal certainty — Principle of proportionality)