This list is based on a smaller subset of Duolingo users, mainly those who somehow happened to get listed in the Streak Hall of Fame with a 100+ days streak, excluding those who never went further than level 1 in a given language, for this very reason the overall statistics data is indeed more or less off and the judgements you can make based on these lists would be more or less biased depending on the number of users per list. Hope this helps.
By default the list is sorted by name; columns are sortable, slower for longer lists.