I'm a French native, began English when I was 13 (German is my first "school language") although I used basics of English before (to play some games, use DOS). The test estimates my vocabulary size to be 21,100. There is _no way_ that I know that much words. I think it's biased a lot for foreigners, particularly French ones (which gives you a lot of formal English words "for free"). And even more when you have taken 3 years of latin, 1 of greek.