condition mean min max ZT0-3 14.652713 14.652713 14.652713 ZT4-7 15.5925855 15.5925855 15.5925855 ZT8-11 14.3040615 14.3040615 14.3040615 ZT12-15 14.598303999999999 14.598303999999999 14.598303999999999 ZT16-19 13.5511315 13.5511315 13.5511315 ZT20-23 13.506078500000001 13.506078500000001 13.506078500000001