condition mean min max ZT0-3 18.494553 18.494553 18.494553 ZT4-7 24.457061500000002 24.457061500000002 24.457061500000002 ZT8-11 20.8219725 20.8219725 20.8219725 ZT12-15 16.1656645 16.1656645 16.1656645 ZT16-19 22.0130795 22.0130795 22.0130795 ZT20-23 25.0969135 25.0969135 25.0969135