condition mean min max ZT0-3 0.1950970833333333 0.07040425 0.29081199999999996 ZT4-7 0.09344540000000001 0.09344540000000001 0.09344540000000001 ZT8-11 0.0690791 0.0690791 0.0690791 ZT12-15 0.224229 0.18794 0.260518 ZT16-19 0.30030599999999996 0.30030599999999996 0.30030599999999996 ZT20-23 0.4282225 0.4282225 0.4282225