The sentence Perhaps that also says something about nat...

the error rate in reading comprehension is a relevant issue among native English speakers and among non-native ones.

non-native English flight personnel are equally liable to work-related reading comprehension flaws as the native staff.

native English speakers’ reading comprehension error rate is found to be less than one-fifth that of non-native English speakers.

Simplified English used in documentation is mandatory for non-native English speakers to appropriately function in the work environment.

native speakers of English have had substantial difficulty speaking to non-native speakers in the aircraft maintenance work environment.