condition mean min max ZT0-3 8.547216666666667 7.18152 10.40897 ZT4-7 7.76635 7.76635 7.76635 ZT8-11 6.3539650000000005 6.3539650000000005 6.3539650000000005 ZT12-15 8.880725 8.3354 9.42605 ZT16-19 6.956015 6.956015 6.956015 ZT20-23 8.96658 8.96658 8.96658