condition mean min max ZT0-3 24.478888 24.478888 24.478888 ZT4-7 29.7451805 29.7451805 29.7451805 ZT8-11 28.713843 28.713843 28.713843 ZT12-15 22.776381999999998 22.776381999999998 22.776381999999998 ZT16-19 25.857031 25.857031 25.857031 ZT20-23 27.560935999999998 27.560935999999998 27.560935999999998