condition mean min max ZT0-3 60.122306 60.122306 60.122306 ZT4-7 57.8449775 57.8449775 57.8449775 ZT8-11 58.4273355 58.4273355 58.4273355 ZT12-15 65.327967 65.327967 65.327967 ZT16-19 49.337168 49.337168 49.337168 ZT20-23 53.811081 53.811081 53.811081