Number systems of the world, sorted by complexity of counting (2006)
I don't understand how the author is judging complexity.  The top one, Huli, is a base-15 number system but looks quite regular otherwise.  French, on the other hand, switches from a base-10 to a base-20 at 80 and then switches things up at 97.According to the listing, Welsh sits somewhere between these two but it has separate numbering systems for {20s, 40s, 60s, 80s}, {30s, 70s, 90s}, and {50s}.  That seems much more complicated than either Huli or French.