condition mean min max ZT0-3 13.714701 13.714701 13.714701 ZT4-7 13.21123 13.21123 13.21123 ZT8-11 15.0401855 15.0401855 15.0401855 ZT12-15 14.356814 14.356814 14.356814 ZT16-19 13.946143 13.946143 13.946143 ZT20-23 13.648225 13.648225 13.648225