I have never seen a Forward Error Correction count on an ADSL router before, presumably the count indicates the number of data errors detected and corrected by the router, and the count you have is significantly large, so I would say high and not normal.
When my modem used to be in VDSL mode, I also used to have HUGH FEC error counts. Like yours. But I just checked and it is currently 0. But the modem has been in ADSL mode for a few weeks.
I do not think you need to worry about FEC error at all.