(6)Bulgaria, Malta and Poland revised in 2016 their performance targets in the key performance area of cost-efficiency for the remaining years of the second reference period, that is, 2017, 2018 and 2019. By Commission Implementing Decision (EU) 2017/2376note, the consistency of those revised targets with the Union-wide performance targets has been established. On the grounds of its assessment, taking account of those revised targets, the Commission has found that the unit rates for en route charging zones for 2017 submitted by Bulgaria, Malta and Poland are in compliance with Implementing Regulations (EU) No 390/2013 and (EU) No 391/2013.