condition mean min max ZT0-3 34.485625 30.144199999999998 38.82705 ZT4-7 23.9925 23.9925 23.9925 ZT8-11 18.874049999999997 18.874049999999997 18.874049999999997 ZT12-15 0 0 0 ZT16-19 25.073549999999997 25.073549999999997 25.073549999999997 ZT20-23 26.30305 26.30305 26.30305