condition mean min max ZT0-3 8.88934 8.88934 8.88934 ZT4-7 6.3184450000000005 6.3184450000000005 6.3184450000000005 ZT8-11 6.1637 6.1637 6.1637 ZT12-15 8.089025 8.089025 8.089025 ZT16-19 7.694495 7.694495 7.694495 ZT20-23 9.239 9.239 9.239