condition mean min max ZT0-3 0.8423673333333332 0.393668 1.5676139999999998 ZT4-7 0.451192 0.451192 0.451192 ZT8-11 0.3236185 0.3236185 0.3236185 ZT12-15 0.5675325 0.0 1.135065 ZT16-19 0.379238 0.379238 0.379238 ZT20-23 1.132841 1.132841 1.132841