condition mean min max ZT0-3 57.362925 56.458999999999996 58.26685 ZT4-7 43.965199999999996 43.965199999999996 43.965199999999996 ZT8-11 31.19395 31.19395 31.19395 ZT12-15 0 0 0 ZT16-19 37.82085 37.82085 37.82085 ZT20-23 37.0597 37.0597 37.0597