condition mean min max ZT0-3 23.1819 18.82045 27.543349999999997 ZT4-7 7.213525 7.213525 7.213525 ZT8-11 6.3243849999999995 6.3243849999999995 6.3243849999999995 ZT12-15 0 0 0 ZT16-19 22.22055 22.22055 22.22055 ZT20-23 16.45195 16.45195 16.45195