455In that regard, it must be noted that, where the Commission has not adopted any guidelines setting out the method of calculation which it is required to follow when setting fines under a particular provision and the Commission’s reasoning is disclosed in a clear and unequivocal fashion in the contested decision, the Commission is not required to express in figures, in absolute terms or as a percentage, the basic amount of the fine and any aggravating or mitigating circumstances (judgments of 15 December 2010, E.ON Energie v Commission, T‑141/08, EU:T:2010:516, paragraph 284, and of 26 November 2014, Energetický a průmyslový and EP Investment Advisors v Commission, T‑272/12, EU:T:2014:995, paragraph 101).