58Finally, with regard to the increase in the amounts of fines over the last few years, the Commission points out, firstly, that the increase in the turnovers of undertakings since the 1960s in itself justifies the freedom of action left to the Commission by the contested provision and, secondly, that, according to settled case-law (Joined Cases 100/80 to 103/80 Musique Diffusion française and Others v Commission [1983] ECR 1825, paragraphs 108 and 109; LR AF 1998 v Commission, cited in paragraph 46 above, paragraph 237; and Joined Cases T-202/98, T-204/98 and T-207/98Tate & Lyle and Others v Commission [2001] ECR II-2035, paragraphs 144 and 145), the Commission must be able to raise the level of fines in order to strengthen their deterrent effect. However, that discretion is not unlimited, since the Court of Justice and the Court of First Instance are to examine whether the increases decided upon by the Commission are justified by the alleged interest (Case T-334/94Sarrió v Commission [1998] ECR II-1439, paragraphs 323 to 335, and Case T-16/99Lögstör Rör v Commission [2002] ECR II-1633, paragraph 251). Finally, it notes that, despite that increase in the level of fines, manifest and serious infringements of long duration remain relatively frequent.