condition mean min max ZT0-3 984.539749 984.539749 984.539749 ZT4-7 1416.2414365 1416.2414365 1416.2414365 ZT8-11 540.1991695 540.1991695 540.1991695 ZT12-15 294.3265245 294.3265245 294.3265245 ZT16-19 157.7503965 157.7503965 157.7503965 ZT20-23 138.93048299999998 138.93048299999998 138.93048299999998