condition mean min max ZT0-3 19.687350000000002 18.9716 20.403100000000002 ZT4-7 21.3328 21.3328 21.3328 ZT8-11 22.604599999999998 22.604599999999998 22.604599999999998 ZT12-15 29.30995 25.9273 32.6926 ZT16-19 23.62 20.898033333333334 26.341966666666668 ZT20-23 0 0 0