condition mean min max ZT0-3 12.434487 12.434487 12.434487 ZT4-7 14.0897075 14.0897075 14.0897075 ZT8-11 11.6611705 11.6611705 11.6611705 ZT12-15 12.905016 12.905016 12.905016 ZT16-19 12.305948 12.305948 12.305948 ZT20-23 12.2678815 12.2678815 12.2678815