The first offence has a max fine of 10%. Second offence has a max fine of 20%, as the article says: "If that investigation confirms that Apple failed to comply

The first offence has a max fine of 10%. Second offence has a max fine of 20%, as the article says: "If that investigation confirms that Apple failed to comply with the antitrust law, then the iPhone maker could be fined up to 10% of its worldwide turnover – increasing to 20% for repeat infringements …"