condition mean min max ZT0-3 11.152963333333332 7.174239999999999 14.933 ZT4-7 6.563610000000001 6.563610000000001 6.563610000000001 ZT8-11 10.372174999999999 10.372174999999999 10.372174999999999 ZT12-15 12.548725000000001 12.5027 12.59475 ZT16-19 12.96385 12.96385 12.96385 ZT20-23 15.82305 15.82305 15.82305