condition mean min max ZT0-3 22.245375 22.245375 22.245375 ZT4-7 22.2086875 22.2086875 22.2086875 ZT8-11 24.3455955 24.3455955 24.3455955 ZT12-15 20.2305915 20.2305915 20.2305915 ZT16-19 23.030904 23.030904 23.030904 ZT20-23 21.268302 21.268302 21.268302