condition mean min max ZT0-3 21.31465 21.31465 21.31465 ZT4-7 18.887700000000002 18.887700000000002 18.887700000000002 ZT8-11 19.16285 19.16285 19.16285 ZT12-15 19.48055 19.48055 19.48055 ZT16-19 21.8286 21.8286 21.8286 ZT20-23 19.3052 19.3052 19.3052