condition mean min max ZT0-3 18.387974999999997 14.12765 22.6483 ZT4-7 18.15175 18.15175 18.15175 ZT8-11 20.340200000000003 20.340200000000003 20.340200000000003 ZT12-15 0 0 0 ZT16-19 29.9497 29.9497 29.9497 ZT20-23 32.719049999999996 32.719049999999996 32.719049999999996