condition mean min max ZT0-3 26.94315 25.29875 28.58755 ZT4-7 32.78725 32.78725 32.78725 ZT8-11 50.08315 50.08315 50.08315 ZT12-15 0 0 0 ZT16-19 55.285799999999995 55.285799999999995 55.285799999999995 ZT20-23 38.7672 38.7672 38.7672