condition mean min max ZT0-3 4.242875 4.242875 4.242875 ZT4-7 2.132915 2.132915 2.132915 ZT8-11 4.75032 4.75032 4.75032 ZT12-15 7.389255 7.389255 7.389255 ZT16-19 8.303485 8.303485 8.303485 ZT20-23 6.329415 6.329415 6.329415