I'm a native speaker. I read a lot. Fiction, nonfiction, literature, etc. I've got a master's degree in CS. I'm a published author at multiple respected conferences. I've been learning Spanish as a second language for ~2 years.
I scored about 33,000. I don't think the distributions are very accurate. I can't speak to where you should be, but I think you have an excellent score. I hope this point of comparison helps.
I also got 33K, ~80th percentile. But, I got 98, 99th percentile on the Verbal section of my GREs (which has a lot of vocabulary, though it isn't only vocabulary). I find it hard to believe there's that big of a gap, though I suppose a lot of foreign applicants could drag down the GRE average, pushing me up. But, it's also possible that people were liberal with their claims to understand words.
I scored about 33,000. I don't think the distributions are very accurate. I can't speak to where you should be, but I think you have an excellent score. I hope this point of comparison helps.