condition mean min max ZT0-3 22.200725 21.3161 23.08535 ZT4-7 18.313299999999998 18.313299999999998 18.313299999999998 ZT8-11 24.7396 24.7396 24.7396 ZT12-15 0 0 0 ZT16-19 21.81465 21.81465 21.81465 ZT20-23 21.399250000000002 21.399250000000002 21.399250000000002