condition mean min max ZT0-3 0.8121781666666665 0.24879849999999998 1.4672999999999998 ZT4-7 0.19325494999999998 0.19325494999999998 0.19325494999999998 ZT8-11 0.4344515 0.4344515 0.4344515 ZT12-15 0.26829075 0.16441299999999998 0.3721685 ZT16-19 0.413384 0.413384 0.413384 ZT20-23 0.255467 0.255467 0.255467