condition mean min max ZT0-3 9.624866 9.624866 9.624866 ZT4-7 8.802574 8.802574 8.802574 ZT8-11 8.9554115 8.9554115 8.9554115 ZT12-15 10.011828 10.011828 10.011828 ZT16-19 8.7880045 8.7880045 8.7880045 ZT20-23 9.534474 9.534474 9.534474