condition mean min max ZT0-3 28.044841 28.044841 28.044841 ZT4-7 22.0546565 22.0546565 22.0546565 ZT8-11 21.801866 21.801866 21.801866 ZT12-15 21.7320845 21.7320845 21.7320845 ZT16-19 23.2482255 23.2482255 23.2482255 ZT20-23 32.257601 32.257601 32.257601