condition mean min max ZT0-3 6.89422 6.15362 7.6348199999999995 ZT4-7 4.807855 4.807855 4.807855 ZT8-11 6.7637149999999995 6.7637149999999995 6.7637149999999995 ZT12-15 0 0 0 ZT16-19 7.75938 7.75938 7.75938 ZT20-23 6.67045 6.67045 6.67045