condition mean min max ZT0-3 261.133736 261.133736 261.133736 ZT4-7 247.5316485 247.5316485 247.5316485 ZT8-11 199.06609400000002 199.06609400000002 199.06609400000002 ZT12-15 274.4854735 274.4854735 274.4854735 ZT16-19 257.1883995 257.1883995 257.1883995 ZT20-23 252.1472295 252.1472295 252.1472295