condition mean min max ZT0-3 1.0613911666666667 0.2954195 2.13463 ZT4-7 1.31502 1.31502 1.31502 ZT8-11 0.7581895 0.7581895 0.7581895 ZT12-15 0.8615992499999999 0.3096735 1.413525 ZT16-19 0.594553 0.594553 0.594553 ZT20-23 0.2809055 0.2809055 0.2809055