condition mean min max ZT0-3 28.985316666666666 26.201700000000002 33.33305 ZT4-7 17.7653 17.7653 17.7653 ZT8-11 13.883600000000001 13.883600000000001 13.883600000000001 ZT12-15 31.763025 26.1766 37.34945 ZT16-19 24.6521 24.6521 24.6521 ZT20-23 33.918099999999995 33.918099999999995 33.918099999999995