condition mean min max ZT0-3 26.71475 25.5201 27.909399999999998 ZT4-7 25.36045 25.36045 25.36045 ZT8-11 22.7829 22.7829 22.7829 ZT12-15 0 0 0 ZT16-19 19.970399999999998 19.970399999999998 19.970399999999998 ZT20-23 26.099249999999998 26.099249999999998 26.099249999999998