condition mean min max ZT0-3 262.861241 262.861241 262.861241 ZT4-7 274.215882 274.215882 274.215882 ZT8-11 312.2635085 312.2635085 312.2635085 ZT12-15 278.400746 278.400746 278.400746 ZT16-19 276.583448 276.583448 276.583448 ZT20-23 271.6168705 271.6168705 271.6168705