condition mean min max ZT0-3 29.767614 29.767614 29.767614 ZT4-7 35.745115999999996 35.745115999999996 35.745115999999996 ZT8-11 35.5445245 35.5445245 35.5445245 ZT12-15 32.5903815 32.5903815 32.5903815 ZT16-19 21.723939 21.723939 21.723939 ZT20-23 23.367691 23.367691 23.367691