condition mean min max ZT0-3 12.057649999999999 11.49785 12.61745 ZT4-7 6.5827100000000005 6.5827100000000005 6.5827100000000005 ZT8-11 12.180299999999999 12.180299999999999 12.180299999999999 ZT12-15 0 0 0 ZT16-19 15.176099999999998 15.176099999999998 15.176099999999998 ZT20-23 13.08755 13.08755 13.08755