condition mean min max ZT0-3 3.0159525 2.80646 3.2254449999999997 ZT4-7 3.072395 3.072395 3.072395 ZT8-11 2.98246 2.98246 2.98246 ZT12-15 0 0 0 ZT16-19 3.533625 3.533625 3.533625 ZT20-23 3.825055 3.825055 3.825055