condition mean min max ZT0-3 4.748855 4.748855 4.748855 ZT4-7 3.81004 3.81004 3.81004 ZT8-11 3.9646299999999997 3.9646299999999997 3.9646299999999997 ZT12-15 3.252085 3.252085 3.252085 ZT16-19 4.668205 4.668205 4.668205 ZT20-23 3.414055 3.414055 3.414055