condition mean min max ZT0-3 15.3158575075 12.82088293 17.810832085 ZT4-7 15.718913807500002 15.309677475 16.128150140000002 ZT8-11 21.79859543 15.87094327 27.72624759 ZT12-15 24.734223345 22.773469305 26.694977385 ZT16-19 18.1743839025 17.670515635 18.67825217 ZT20-23 15.4936764425 14.711010315 16.27634257