condition mean min max ZT0-3 14.3078525 8.923044999999998 19.69266 ZT4-7 24.46595 24.46595 24.46595 ZT8-11 26.71525 26.71525 26.71525 ZT12-15 0 0 0 ZT16-19 28.5081 28.5081 28.5081 ZT20-23 26.43325 26.43325 26.43325