condition mean min max ZT0-3 30.638904 30.638904 30.638904 ZT4-7 25.241201 25.241201 25.241201 ZT8-11 25.5175525 25.5175525 25.5175525 ZT12-15 25.685276 25.685276 25.685276 ZT16-19 26.479264 26.479264 26.479264 ZT20-23 29.416619 29.416619 29.416619