condition mean min max ZT0-3 16.976257 16.976257 16.976257 ZT4-7 24.697548 24.697548 24.697548 ZT8-11 39.225976 39.225976 39.225976 ZT12-15 67.11556 67.11556 67.11556 ZT16-19 20.5943015 20.5943015 20.5943015 ZT20-23 22.5373335 22.5373335 22.5373335