condition mean min max ZT0-3 13.844453 13.844453 13.844453 ZT4-7 16.5887 16.5887 16.5887 ZT8-11 15.421056 15.421056 15.421056 ZT12-15 15.976205 15.976205 15.976205 ZT16-19 11.2535735 11.2535735 11.2535735 ZT20-23 13.944571 13.944571 13.944571