condition mean min max ZT0-3 21.53375 21.53375 21.53375 ZT4-7 23.04205 23.04205 23.04205 ZT8-11 22.4839 22.4839 22.4839 ZT12-15 20.29615 20.29615 20.29615 ZT16-19 14.880199999999999 14.880199999999999 14.880199999999999 ZT20-23 13.54645 13.54645 13.54645