Don't know as of now, but when i chinned during the first 2 weeks of the game i didnt see any pkers ( i also managed to kill golfball and his friend for 50m down there). I used ~10k chins from 75-94 i believe. Red chins you get 1.3-1.6m/xp hr and with black chins you get 1.8-2m xp/hr.