condition mean min max ZT0-3 4.936385 4.513375 5.359395 ZT4-7 4.152245 4.152245 4.152245 ZT8-11 3.1862399999999997 3.1862399999999997 3.1862399999999997 ZT12-15 0 0 0 ZT16-19 4.805895 4.805895 4.805895 ZT20-23 5.348855 5.348855 5.348855