condition mean min max ZT0-3 8.213255 8.213255 8.213255 ZT4-7 6.726025 6.726025 6.726025 ZT8-11 7.11688 7.11688 7.11688 ZT12-15 6.031155 6.031155 6.031155 ZT16-19 7.560485 7.560485 7.560485 ZT20-23 8.25666 8.25666 8.25666