condition mean min max ZT0-3 2.1064203333333333 1.110391 2.6081250000000002 ZT4-7 0.6106609999999999 0.6106609999999999 0.6106609999999999 ZT8-11 0.7115805 0.7115805 0.7115805 ZT12-15 2.6258049999999997 2.4701899999999997 2.78142 ZT16-19 3.2332 3.2332 3.2332 ZT20-23 3.345155 3.345155 3.345155