condition mean min max ZT0-3 3.0126483333333334 2.380905 3.927315 ZT4-7 2.73186 2.73186 2.73186 ZT8-11 2.258345 2.258345 2.258345 ZT12-15 11.54149 5.7653300000000005 17.31765 ZT16-19 5.394965 5.394965 5.394965 ZT20-23 6.01843 6.01843 6.01843