condition mean min max ZT0-3 8.13444 8.13444 8.13444 ZT4-7 5.75641 5.75641 5.75641 ZT8-11 6.16582 6.16582 6.16582 ZT12-15 8.437285 8.437285 8.437285 ZT16-19 8.866340000000001 8.866340000000001 8.866340000000001 ZT20-23 8.09649 8.09649 8.09649