Hmmm not sure about the 4th level you're talking about. First, the 1st level is something like 100goals, then 2nd level 250goals, 3rd 500goals, etc. (I guess, honestly I dont remember the exact previous level but I remember it increases every level unlocked)
And didn't achievement started later than the stats pages appeared ? So I don't know if it take in consideration every goal the statistics page show you.