condition mean min max ZT0-3 13.585566 13.585566 13.585566 ZT4-7 13.934828 13.934828 13.934828 ZT8-11 14.8188685 14.8188685 14.8188685 ZT12-15 14.989186 14.989186 14.989186 ZT16-19 15.524897 15.524897 15.524897 ZT20-23 14.524473 14.524473 14.524473