condition mean min max ZT0-3 95.476257 95.476257 95.476257 ZT4-7 59.744861 59.744861 59.744861 ZT8-11 41.521043000000006 41.521043000000006 41.521043000000006 ZT12-15 40.3922335 40.3922335 40.3922335 ZT16-19 34.9907035 34.9907035 34.9907035 ZT20-23 30.230767999999998 30.230767999999998 30.230767999999998