condition mean min max ZT0-3 2.6178600000000003 2.6178600000000003 2.6178600000000003 ZT4-7 2.818755 2.818755 2.818755 ZT8-11 2.953035 2.953035 2.953035 ZT12-15 2.15577 2.15577 2.15577 ZT16-19 4.002185 4.002185 4.002185 ZT20-23 2.744215 2.744215 2.744215