condition mean min max ZT0-3 19.970378 19.970378 19.970378 ZT4-7 18.873171 18.873171 18.873171 ZT8-11 21.335912 21.335912 21.335912 ZT12-15 18.0137125 18.0137125 18.0137125 ZT16-19 22.552373 22.552373 22.552373 ZT20-23 21.628525500000002 21.628525500000002 21.628525500000002