condition mean min max ZT0-3 20671.77183 20671.77183 20671.77183 ZT4-7 19247.63092 19247.63092 19247.63092 ZT8-11 19635.25514 19635.25514 19635.25514 ZT12-15 20750.527195000002 20750.527195000002 20750.527195000002 ZT16-19 21876.331684999997 21876.331684999997 21876.331684999997 ZT20-23 20037.64847 20037.64847 20037.64847