Judgment of the Court of First Instance of 29 April 2004 in Joined Cases T-236/01, T-239/01, T-244/01 to T-246/01, T-251/01 and T-252/01: Tokai Carbon Co. Ltd and Others v Commission of the European Communities (Competition — Appeal — Cartel — Graphite electrodes market — Price-fixing and market-sharing — Calculation of fines — Concurrent sanctions — Guidelines on the method of setting fines — Applicability — Gravity and duration of the infringement — Aggravating circumstances — Attenuating circumstances — Ability to pay — Cooperation during the administrative procedure — Arrangements for payment)