Non native, 81%. I think the test might be easier for non-natives speaking european native languages, as they cumulate etymological understanding from several languages.
I'd also guess that non-native speakers are less likely to say "yes" to fake words. Non-native speakers are, presumably, more self-aware of the extents and limitations of their English vocabularies. Native speakers seem more likely to succumb to issues of vanity, overconfidence, or bet-hedging on this sort of test.
